Prerequisites for the Phone Proxy
This section contains the following topics:
Media Termination Instance Prerequisites
The ASA must have a media termination instance that meets the following criteria:
- You must configure one media termination for each phone proxy on the ASA. Multiple media termination instances on the ASA are not supported.
- For the media termination instance, you can configure a global media-termination address for all interfaces or configure a media-termination address for different interfaces. However, you cannot use a global media-termination address and media-termination addresses configured for each interface at the same time.
- If you configure a media termination address for multiple interfaces, you must configure an address on each interface that the ASA uses when communicating with IP phones.
For example, if you had three interfaces on the ASA (one internal interface and two external interfaces) and only one of the external interfaces were used to communicate with IP phones, you would configure two media termination addresses: one on the internal interface and one on the external interface that communicated with the IP phones.
- Only one media-termination address can be configured per interface.
- The IP addresses are publicly routable addresses that are unused IP addresses within the address range on that interface.
- The IP address on an interface cannot be the same address as that interface on the ASA.
- The IP addresses cannot overlap with existing static NAT pools or NAT rules.
- The IP addresses cannot be the same as the Cisco UCM or TFTP server IP address.
- For IP phones behind a router or gateway, you must also meet this prerequisite. On the router or gateway, add routes to the media termination address on the ASA interface that the IP phones communicate with so that the phone can reach the media termination address.
Certificates from the Cisco UCM
Import the following certificates which are stored on the Cisco UCM. These certificates are required by the ASA for the phone proxy.
- Cisco_Manufacturing_CA
- CAP-RTP-001
- CAP-RTP-002
- CAPF certificate (Optional)
If LSC provisioning is required or you have LSC enabled IP phones, you must import the CAPF certificate from the Cisco UCM. If the Cisco UCM has more than one CAPF certificate, you must import all of them to the ASA.
Note You can configure LSC provisioning for additional end-user authentication. See the Cisco Unified Communications Manager configuration guide for information.
See Importing Certificates from the Cisco UCM. For example, the CA Manufacturer certificate is required by the phone proxy to validate the IP phone certificate.
DNS Lookup Prerequisites
- If you have an fully qualified domain name (FQDN) configured for the Cisco UCM rather than an IP address, you must configure and enable DNS lookup on the ASA. For information about the dns domain-lookup command and how to use it to configure DNS lookup, see command reference.
- After configuring the DNS lookup, make sure that the ASA can ping the Cisco UCM with the configured FQDN.
- You must configure DNS lookup when you have a CAPF service enabled and the Cisco UCM is not running on the Publisher but the Publisher is configured with a FQDN instead of an IP address.
Cisco Unified Communications Manager Prerequisites
- The TFTP server must reside on the same interface as the Cisco UCM.
- The Cisco UCM can be on a private network on the inside but you need to have a static mapping for the Cisco UCM on the ASA to a public routable address.
- If NAT is required for Cisco UCM, it must be configured on the ASA, not on the existing firewall.
Access List Rules
If the phone proxy is deployed behind an existing firewall, access-list rules to permit signaling, TFTP requests, and media traffic to the phone proxy must be configured.
If NAT is configured for the TFTP server or Cisco UCMs, the translated “global” address must be used in the access lists.
Table 48-1 lists the ports that are required to be configured on the existing firewall:
Table 48-1 Port Configuration Requirements
|
|
|
|
Media Termination |
1024-65535 |
UDP |
Allow incoming SRTP |
TFTP Server |
69 |
UDP |
Allow incoming TFTP |
Cisco UCM |
2443 |
TCP |
Allow incoming secure SCCP |
Cisco UCM |
5061 |
TCP |
Allow incoming secure SIP |
CAPF Service (on Cisco UCM) |
3804 |
TCP |
Allow CAPF service for LSC provisioning |
Note All these ports are configurable on the Cisco UCM, except for TFTP. These are the default values and should be modified if they are modified on the Cisco UCM. For example, 3804 is the default port for the CAPF Service. This default value should be modified if it is modified on the Cisco UCM.
NAT and PAT Prerequisites
NAT Prerequisites
- If NAT is configured for the TFTP server, the NAT configuration must be configured prior to configuring the tftp-server command under the phone proxy.
- If NAT is configured for the TFTP server or Cisco UCMs, the translated “global” address must be used in the access lists.
PAT Prerequisites
- When the Skinny inspection global port is configured to use a non-default port, then you must configure the nonsecure port as the
global_sccp_port+443
.
Therefore, if global_sccp_port is 7000, then the global secure SCCP port is 7443. Reconfiguring the port might be necessary when the phone proxy deployment has more than one Cisco UCM and they must share the interface IP address or a global IP address.
/* use the default ports for the first CUCM */
object network obj-10.0.0.1-01
nat (inside,outside) static interface service tcp 2000 2000
object network obj-10.0.0.1-02
nat (inside,outside) static interface service tcp 2443 2443
/* use non-default ports for the 2nd CUCM */
object network obj-10.0.0.2-01
nat (inside,outside) static interface service tcp 2000 7000
object network obj-10.0.0.2-02
nat (inside,outside) static interface service tcp 2443 7443
Note Both PAT configurations—for the nonsecure and secure ports—must be configured.
- When the IP phones must contact the CAPF on the Cisco UCM and the Cisco UCM is configured with static PAT (LCS provisioning is required), you must configure static PAT for the default CAPF port 3804.
Prerequisites for IP Phones on Multiple Interfaces
When IP phones reside on multiple interfaces, the phone proxy configuration must have the correct IP address set for the Cisco UCM in the CTL file.
See the following example topology for information about how to correctly set the IP address:
|----- ASA PP --- (outside Internet) --- phones
In this example topology, the following IP address are set:
- Cisco UCM on the inside interface is set to 10.0.0.5
- The DMZ network is 192.168.1.0/24
- The inside network is 10.0.0.0/24
The Cisco UCM is mapped with different global IP addresses from DMZ > outside and inside interfaces > outside interface.
In the CTL file, the Cisco UCM must have two entries because of the two different IP addresses. For example, if the static statements for the Cisco UCM are as follows:
object network obj-10.0.0.5-01
nat (inside,outside) static 209.165.202.129
object network obj-10.0.0.5-02
nat (inside,dmz) static 198.168.1.2
There must be two CTL file record entries for the Cisco UCM:
record-entry cucm trustpoint cucm_in_to_out address 209.165.202.129
record-entry cucm trustpoint cucm_in_to_dmz address 192.168.1.2
7960 and 7940 IP Phones Support
- An LSC must be installed on these IP phones because they do not come pre installed with a MIC. Install the LSC on each phone before using them with the phone proxy to avoid opening the nonsecure SCCP port for the IP phones to register in nonsecure mode with the Cisco UCM.
See the following document for the steps to install an LSC on IP phones:
http://www.cisco.com/en/US/docs/voice_ip_comm/cucm/security/7_0_1/secugd/secucapf.html#wp1093518
Note If an IP phone already has an LSC installed on it from a different Cisco UCM cluster, delete the LSC from the different cluster and install an LSC from the current Cisco UCM cluster.
Note You can configure LSC provisioning for additional end-user authentication. See the Cisco Unified Communications Manager configuration guide for information.
- The CAPF certificate must be imported onto the ASA.
- The CTL file created on the ASA must be created with a CAPF record-entry.
- The phone must be configured to use only the SCCP protocol because the SIP protocol does not support encryption on these IP phones.
- If LSC provisioning is done via the phone proxy, you must add an ACL to allow the IP phones to register with the Cisco UCM on the nonsecure port 2000.
Cisco IP Communicator Prerequisites
To configure Cisco IP Communicator (CIPC) with the phone proxy, you must meet the following prerequisites:
- Include the cipc security-mode authenticated command under the phone-proxy command when configuring the phone proxy instance.
- Create an ACL to allow CIPC to register with the Cisco UCM in nonsecure mode.
- Configure null-sha1 as one of the SSL encryption ciphers.
Current versions of Cisco IP Communicator (CIPC) support authenticated mode and perform TLS signaling but not voice encryption. Therefore, you must include the following command when configuring the phone proxy instance:
cipc security-mode authenticated
Because CIPC requires an LSC to perform the TLS handshake, CIPC needs to register with the Cisco UCM in nonsecure mode using cleartext signaling. To allow the CIPC to register, create an ACL that allows the CIPC to connect to the Cisco UCM on the nonsecure SIP/SCCP signalling ports (5060/2000).
Note You can configure LSC provisioning for additional end-user authentication. See the Cisco Unified Communications Manager configuration guide for information.
CIPC uses a different cipher when doing the TLS handshake and requires the null-sha1 cipher and SSL encryption be configured. To add the null-shal cipher, use the show run all ssl command to see the output for the ssl encryption command and add null-shal to the end of the SSL encryption list.
Note When used with CIPC, the phone proxy does not support end-users resetting their device name in CIPC (Preferences > Network tab > Use this Device Name field) or Administrators resetting the device name in Cisco Unified CM Administration console (Device menu > Phone Configuration > Device Name field). To function with the phone proxy, the CIPC configuration file must be in the format: SEP<mac_address>.cnf.xml. If the device name does not follow this format (SEP<mac_address>), CIPC cannot retrieve its configuration file from Cisco UMC via the phone proxy and CIPC will not function.
Prerequisites for Rate Limiting TFTP Requests
In a remote access scenario, we recommend that you configure rate limiting of TFTP requests because any IP phone connecting through the Internet is allowed to send TFTP requests to the TFTP server.
To configure rate limiting of TFTP requests, configure the police command in the Modular Policy Framework. See the command reference for information about using the police command.
Policing is a way of ensuring that no traffic exceeds the maximum rate (in bits/second) that you configure, thus ensuring that no one traffic flow can take over the entire resource. When traffic exceeds the maximum rate, the ASA drops the excess traffic. Policing also sets the largest single burst of traffic allowed.
Rate Limiting Configuration Example
The following example describes how you configure rate limiting for TFTP requests by using the police command and the Modular Policy Framework.
Begin by determining the conformance rate that is required for the phone proxy. To determine the conformance rate, use the following formula:
Where
X = requests per second
Y = size of each packet, which includes the L2, L3, and L4 plus the payload
Therefore, if a rate of 300 TFTP requests/second is required, then the conformance rate would be calculated as follows:
300 requests/second * 80 bytes * 8 = 192000
The example configuration below shows how the calculated conformance rate is used with the police command:
access-list tftp extended permit udp any host 192.168.0.1 eq tftp
service-policy tftpmap interface inside
About ICMP Traffic Destined for the Media Termination Address
To control which hosts can ping the media termination address, use the icmp command and apply the access rule to the outside interface on the ASA.
Any rules for ICMP access applied to the outside interface apply to traffic destined for the media termination address.
For example, use the following command to deny ICMP pings from any host destined for the media termination address:
icmp deny any outside
End-User Phone Provisioning
The phone proxy is a transparent proxy with respect to the TFTP and signaling transactions. If NAT is not configured for the Cisco UCM TFTP server, then the IP phones need to be configured with the Cisco UCM cluster TFTP server address.
If NAT is configured for the Cisco UCM TFTP server, then the Cisco UCM TFTP server global address is configured as the TFTP server address on the IP phones.
Ways to Deploy IP Phones to End Users
In both options, deploying a remote IP phone behind a commercial Cable/DSL router with NAT capabilities is supported.
Option 1 (Recommended)
Stage the IP phones at corporate headquarters before sending them to the end users:
- The phones register inside the network. IT ensures there are no issues with the phone configurations, image downloads, and registration.
- If Cisco UCM cluster was in mixed mode, the CTL file should be erased before sending the phone to the end user.
Advantages of this option are:
- Easier to troubleshoot and isolate problems with the network or phone proxy because you know whether the phone is registered and working with the Cisco UCM.
- Better user experience because the phone does not have to download firmware from over a broadband connection, which can be slow and require the user to wait for a longer time.
Option 2
Send the IP phone to the end user. When using option 2, the user must be provided instructions to change the settings on phones with the appropriate Cisco UCM and TFTP server IP address.
Note As an alternative to authenticating remote IP phones through the TLS handshake, you can configure authentication via LSC provisioning. With LSC provisioning you create a password for each remote IP phone user and each user enters the password on the remote IP phones to retrieve the LSC.
Because using LSC provisioning to authenticate remote IP phones requires the IP phones first register in nonsecure mode, Cisco recommends LSC provisioning be done inside the corporate network before giving the IP phones to end-users. Otherwise, having the IP phones register in nonsecure mode requires the Administrator to open the nonsecure signaling port for SIP and SCCP on the ASA.
See “Example 5: LSC Provisioning in Mixed-mode Cisco UCM cluster; Cisco UCM and TFTP Server on Publisher“. See also the Cisco Unified Communications Manager Security Guide for information on Using the Certificate Authority Proxy Function (CAPF) to install a locally significant certificate (LSC).
Configuring the Phone Proxy
This section includes the following topics:
Importing Certificates from the Cisco UCM
For the TLS proxy used by the phone proxy to complete the TLS handshake successfully, it needs to verify the certificates from the IP phone (and the Cisco UCM if doing TLS with Cisco UCM). To validate the IP phone certificate, we need the CA Manufacturer certificate which is stored on the Cisco UCM. Follow these steps to import the CA Manufacturer certificate to the ASA.
Step 1 Go to the Cisco UCM Operating System Administration web page.
Step 2 Choose Security > Certificate Management.
Note Earlier versions of Cisco UCM have a different UI and way to locate the certificates. For example, in Cisco UCM version 4.x, certificates are located in the directory C:\Program Files\Cisco\Certificates
. See your Cisco Unified Communications Manager (CallManager) documentation for information about locating certificates.
Step 3 Click Find and it will display all the certificates.
Step 4 Find the filename Cisco_Manufacturing_CA
. This is the certificate need to verify the IP phone certificate. Click the.PEM file Cisco_Manufacturing_CA.pem
. This will show you the certificate information and a dialog box that has the option to download the certificate.
Note If the certificate list contains more than one certificate with the filename Cisco_Manufacturing_CA
, make you select the certificate Cisco_Manufacturing_CA.pem
—the one with the.pem file extension.
Step 5 Click Download and save the file as a text file.
Step 6 On the ASA, create a trustpoint for the Cisco Manufacturing CA and enroll via terminal by entering the following commands. Enroll via terminal because you will paste the certificate you downloaded in Step 4.
hostname(config)# crypto ca trustpoint trustpoint_name
hostname(config-ca-trustpoint)# enrollment terminal
Step 7 Authenticate the trustpoint by entering the following command:
hostname(config)# crypto ca authenticate trustpoint
Step 8 You are prompted to “Enter the base 64 encoded CA Certificate.” Copy the.PEM file you downloaded in Step 4 and paste it at the command line. The file is already in base-64 encoding so no conversion is required. If the certificate is OK, you are prompted to accept it: “Do you accept this certificate? [yes/no].” Enter yes.
Note When you copy the certificate, make sure that you also copy also the lines with BEGIN and END.
Tip If the certificate is not ok, use the debug crypto ca command to show debug messages for PKI activity (used with CAs).
Step 9 Repeat the Step 1 through Step 8 for the next certificate. Table 48-2 shows the certificates that are required by the ASA.
Table 48-2 Certificates Required by the Security Appliance for the Phone Proxy
|
|
CallManager |
Authenticating the Cisco UCM during TLS handshake; only required for mixed-mode clusters. |
Cisco_Manufacturing_CA |
Authenticating IP phones with a Manufacturer Installed Certificate (MIC). |
CAP-RTP-001 |
Authenticating IP phones with a MIC. |
CAP-RTP-002 |
Authenticating IP phones with a MIC. |
CAPF |
Authenticating IP phones with an LSC. |
Task Flow for Configuring the Phone Proxy in a Mixed-mode Cisco UCM Cluster
Note For mixed-mode clusters, the phone proxy does not support the Cisco Unified Call Manager using TFTP to send encrypted configuration files to IP phones through the ASA.
Follow these tasks to configure the phone proxy in a Non-secure Cisco UCM Cluster:
Step 1 Create trustpoints and generate certificates for each entity in the network (Cisco UCM, Cisco UCM and TFTP, TFTP server, CAPF) that the IP phone must trust. The certificates are used in creating the CTL file. See Creating Trustpoints and Generating Certificates.
Note Before you create the trustpoints and generate certificates, you must have imported the required certificates, which are stored on the Cisco UCM. See Certificates from the Cisco UCM and Importing Certificates from the Cisco UCM
Step 2 Create the CTL file for the phone proxy. See Creating the CTL File.
Note When the phone proxy is being configured to run in mixed-mode clusters, you have the following option to use an existing CTL file to install the trustpoints. See Using an Existing CTL File.
Step 3 Create the TLS proxy instance. See Creating the TLS Proxy for a Mixed-mode Cisco UCM Cluster.
Step 4 Create the media termination instance for the phone proxy. See Creating the Media Termination Instance.
Step 5 Create the phone proxy instance. See Creating the Phone Proxy Instance.
Step 6 While configuring the phone proxy instance (in the Phone Proxy Configuration mode), enter the following command to configure the mode of the cluster to be mixed mode because the default is nonsecure:
hostname(config-phone-proxy)# cluster-mode mixed
Step 7 Enable the phone proxy y with SIP and Skinny inspection. See Enabling the Phone Proxy with SIP and Skinny Inspection.
Creating Trustpoints and Generating Certificates
Create trustpoints and generate certificates for each entity in the network (Cisco UCM, Cisco UCM and TFTP, TFTP server, CAPF) that the IP phone must trust. The certificates are used in creating the CTL file.
You need to create trustpoints for each Cisco UCM (primary and secondary if a secondary Cisco UCM is used) and TFTP server in the network. The trustpoints need to be in the CTL file for the phones to trust the Cisco UCM.
Prerequisites
Import the required certificates, which are stored on the Cisco UCM. See Certificates from the Cisco UCM and Importing Certificates from the Cisco UCM.
|
|
|
Step 1 |
hostname(config)#
crypto key generate rsa label
key-pair-label
modulus
size
crypto key generate rsa label cucmtftp_kp modulus 1024
|
Creates a keypair that can be used for the trustpoints. |
Step 2 |
hostname(config)#
crypto ca trustpoint
trustpoint_name
crypto ca trustpoint cucm_tftp_server
|
Creates the trustpoints for each entity in the network (primary Cisco UCM, secondary Cisco UCM, and TFTP server). Note You are only required to create a separate trustpoint for the TFTP server when the TFTP server resides on a different server from the Cisco UCM. See Example 3: Mixed-mode Cisco UCM cluster, Cisco UCM and TFTP Server on Different Servers for an example of this configuration. |
Step 3 |
hostname(config-ca-trustpoint)#
enrollment self
|
Generates a self-signed certificate. |
Step 4 |
hostname(config-ca-trustpoint)#
keypair
keyname
|
Specifies the keypair whose public key is being certified. |
Step 5 |
hostname(config-ca-trustpoint)#
exit
|
Exits from the Configure Trustpoint mode. |
Step 6 |
hostname(config)#
crypto ca enroll
trustpoint
crypto ca enroll cucm_tftp_server
|
Requests the certificate from the CA server and causes the ASA to generate the certificate. When prompted to include the device serial number in the subject name, type Y to include the serial number or type N to exclude it. When prompted to generate the self-signed certificate, type Y. |
What to Do Next
Once you have created the trustpoints and generated the certificates, create the CTL file for the phone proxy. See Creating the CTL File.
If you are configuring the phone proxy in a mixed-mode cluster, you can use an existing CTL file. See Using an Existing CTL File.
Creating the CTL File
Create the CTL file that will be presented to the IP phones during the TFTP requests.
Prerequisites
If you are using domain names for your Cisco UCM and TFTP server, you must configure DNS lookup on the ASA. Add an entry for each of the outside interfaces on the ASA into your DNS server, if such entries are not already present. Each ASA outside IP address should have a DNS entry associated with it for lookups. These DNS entries must also be enabled for Reverse Lookup.
Enable DNS lookups on your ASA with the dns domain-lookup interface_name command (where the interface_name specifies the interface that has a route to your DNS server). Additionally, define your DNS server IP address on the ASA; for example: dns name-server 10.2.3.4
(IP address of your DNS server).
Note You can enter the dns domain-lookup command multiple times to enable DNS lookup on multiple interfaces. If you enter multiple commands, the ASA tries each interface in the order it appears in the configuration until it receives a response.
See the command reference for information about the dns domain-lookup command.
|
|
|
Step 1 |
hostname(config)#
ctl-file
ctl_name
|
Creates the CTL file instance. |
Step 2 |
hostname(config-ctl-file)#
record-entry tftp trustpoint
trustpoint_name
address
TFTP_IP_address
record-entry cucm-tftp trustpoint cucm_tftp_server address 10.10.0.26
|
Creates the record entry for the TFTP server. Note Use the global or mapped IP address of the TFTP server or Cisco UCM if NAT is configured. |
Step 3 |
hostname(config-ctl-file)#
record-entry cucm trustpoint
trustpoint_name
address
IP_address
record-entry cucm trustpoint cucm_server address 10.10.0.26
|
Creates the record entry for the each Cisco UCM (primary and secondary). Note Use the global or mapped IP address of the Cisco UCM. |
Step 4 |
hostname(config-ctl-file)#
record-entry capf trustpoint
trust_point
address
record-entry capf trustpoint capf address 10.10.0.26
|
Creates the record entry for CAPF. Note You only enter this command when LSC provisioning is required or you have LSC enabled IP phones. |
Step 5 |
hostname(config-ctl-file)#
no shutdown
|
Creates the CTL file. When the file is created, it creates an internal trustpoint used by the phone proxy to sign the TFTP files. The trustpoint is named _internal_PP_ ctl-instance_filename. |
Step 6 |
hostname(config)#
copy running-configuration startup-configuration
|
Saves the certificate configuration to Flash memory. |
What to Do Next
Once you have configured the CTL file for the phone proxy, create the TLS proxy instance. See Creating the TLS Proxy Instance for a Non-secure Cisco UCM Cluster to add the TLS proxy when configuring the phone proxy in a non-secure mode or see Creating the TLS Proxy for a Mixed-mode Cisco UCM Cluster if the phone proxy is running in a mixed-mode cluster.
Using an Existing CTL File
Note Only when the phone proxy is running in mixed-mode clusters, you have the option to use an existing CTL file to install trustpoints.
If you have an existing CTL file that contains the correct IP addresses of the entities (namely, the IP address that the IP phones use for the Cisco UCM or TFTP servers), you can be use it to create a new CTL file thereby using the existing CTL file to install the trustpoints for each entity in the network (Cisco UCM, Cisco UCM and TFTP, TFTP server, CAPF) that the IP phones must trust.
Prerequisites
If a CTL file exists for the cluster, copy the CTL file to Flash memory. When you copy the CTL file to Flash memory, rename the file and do not name the file CTLFile.tlv
.
If you are using domain names for your Cisco UCM and TFTP server, you must configure DNS lookup on the ASA. See the prerequisites for Creating the CTL File.
|
|
|
Step 1 |
hostname(config)#
ctl-file
ctl_name
|
Creates the CTL file instance. |
Step 2 |
hostname(config-ctl-file)#
cluster-ctl-file
filename_path
hostname(config-ctl-file)# cluster-ctl-file disk0:/old_ctlfile.tlv
|
Uses the trustpoints that are already in the existing CTL file stored in Flash memory. Where the existing CTL file was saved to Flash memory with a filename other than CTLFile.tlv ; for example, old_ctlfile.tlv . |
What to Do Next
When using an existing CTL file to configure the phone proxy, you can add additional entries to the file as necessary. See Creating the CTL File.
Once you have configured the CTL file for the phone proxy, create the TLS proxy instance. See Creating the TLS Proxy Instance for a Non-secure Cisco UCM Cluster to add the TLS proxy when configuring the phone proxy in a non-secure mode or see Creating the TLS Proxy for a Mixed-mode Cisco UCM Cluster if the phone proxy is running in a mixed-mode cluster.
Creating the TLS Proxy Instance for a Non-secure Cisco UCM Cluster
Create the TLS proxy instance to handle the encrypted signaling.
|
|
|
Step 1 |
hostname(config)#
tls-proxy
proxy_name
|
Creates the TLS proxy instance. |
Step 2 |
hostname(config-tlsp)# server trust-point _internal_PP_ ctl-instance_filename
server trust-point _internal_PP_myctl
|
Configures the server trustpoint and references the internal trustpoint named _internal_PP _ctl-instance_filename. |
What to Do Next
Once you have created the TLS proxy instance, create the phone proxy instance. See Creating the Phone Proxy Instance.
Creating the TLS Proxy for a Mixed-mode Cisco UCM Cluster
For mixed mode clusters, there might be IP phones that are already configured as encrypted so it requires TLS to the Cisco UCM. You must configure the LDC issuer for the TLS proxy.
|
|
|
Step 1 |
hostname(config)#
crypto key generate rsa label
key-pair-label
modulus
size
hostname(config)# crypto key generate rsa label ldc_signer_key modulus 1024
hostname(config)# crypto key generate rsa label phone_common modulus 1024
|
Creates the necessary RSA key pairs. Where the key-pair-label is the LDC signer key and the key for the IP phones. |
Step 2 |
hostname(config)#
crypto ca trustpoint
trustpoint_name
hostname(config)# crypto ca trustpoint ldc_server
|
Creates an internal local CA to sign the LDC for Cisco IP phones. Where the trustpoint_name is for the LDC. |
Step 3 |
hostname(config-ca-trustpoint)#
enrollment self
|
Generates a self-signed certificate. |
Step 4 |
hostname(config-ca-trustpoint)#
proxy-ldc-issuer
|
Defines the local CA role for the trustpoint to issue dynamic certificates for the TLS proxy. |
Step 5 |
hostname(config-ca-trustpoint)#
fqdn
fqdn
hostname(config-ca-trustpoint)# fqdn my_ldc_ca.example.com
|
Includes the indicated FQDN in the Subject Alternative Name extension of the certificate during enrollment. Where the fqdn is for the LDC. |
Step 6 |
hostname(config-ca-trustpoint)#
subject-name
X.500_name
hostname(config-ca-trustpoint)# subject-name cn=FW_LDC_SIGNER_172_23_45_200
|
Includes the indicated subject DN in the certificate during enrollment Where the X.500_name is for the LDC. Use commas to separate attribute-value pairs. Insert quotation marks around any value that contains commas or spaces. For example: cn=crl,ou=certs,o="cisco systems, inc.",c=US The maximum length is 500 characters. |
Step 7 |
hostname(config-ca-trustpoint)#
keypair
keypair
hostname(config-ca-trustpoint)# keypair ldc_signer_key
|
Specifies the key pair whose public key is to be certified. Where the keypair is for the LDC. |
Step 8 |
hostname(config)#
crypto ca enroll
ldc_server
hostname(config)# crypto ca enroll ldc_server
|
Starts the enrollment process with the CA. |
Step 9 |
hostname(config)#
tls-proxy
proxy_name
|
Creates the TLS proxy instance. |
Step 10 |
hostname(config-tlsp)#
server trust-point
_internal_PP_
ctl-instance_filename
hostname(config-tlsp)# server trust-point _internal_PP_myctl
|
Configures the server trustpoint and references the internal trustpoint named _internal_PP _ctl-instance_filename. |
Step 11 |
hostname(config-tlsp)#
client ldc issuer
ca_tp_name
client ldc issuer ldc_server
|
Specifies the local CA trustpoint to issue client dynamic certificates. |
Step 12 |
hostname(config-tlsp)#
client ldc keypair
key_label
hostname(config-tlsp)# client ldc keypair phone_common
|
Specifies the RSA keypair to be used by client dynamic certificates. |
Step 13 |
hostname(config-tlsp)#
client cipher-suite
cipher-suite
hostname(config-tlsp)# client cipher-suite aes128-sha1 aes256-sha1
|
Specifies the cipher suite. Options include des-sha1, 3des-sha1, aes128-sha1, aes256-sha1, or null-sha1. |
Step 14 |
|
Exports the local CA certificate and installs it as a trusted certificate on the Cisco Unified Communications Manager server by performing one of the following actions. |
|
hostname(config)#
crypto ca export
trustpoint
identity-certificate
hostname(config)# crypto ca export ldc_server identity-certificate
|
Exports the certificate if a trustpoint with proxy-ldc-issuer is used as the signer of the dynamic certificates. |
|
hostname(config)#
show crypto ca server certificates
|
Exports the certificate for the embedded local CA server LOCAL-CA-SERVER. After exporting the certificate, you must save the output to a file and import it on the Cisco Unified Communications Manager. You can use the Display Certificates function in the Cisco Unified Communications Manager software to verify the installed certificate. For information about performing these procedures, see the following URLs: http://www.cisco.com/en/US/docs/voice_ip_comm/cucm/cucos/5_0_4/iptpch6.html#wp1040848 http://www.cisco.com/en/US/docs/voice_ip_comm/cucm/cucos/5_0_4/iptpch6.html#wp1040354 |
What To Do Next
Once you have created the TLS proxy instance and installed the certificate on the Cisco Unified Communications Manager, create the phone proxy instance. See Creating the Phone Proxy Instance.
Creating the Media Termination Instance
Create the media termination instance that you will use in the phone proxy.
The media termination address you configure must meet the requirements as described in Media Termination Instance Prerequisites.
|
|
|
Step 1 |
hostname(config)#
media-termination
instance_name
hostname(config)#
media-termination
mediaterm1
|
Creates the media termination instance that you attach to the phone proxy. |
Step 2 |
hostname(config-media-termination)#
address
ip_address [
interface
intf_name ]
hostname(config-media-termination)# address 192.0.2.25 interface inside
hostname(config-media-termination)# address 10.10.0.25 interface outside
|
Configures the media-termination address used by the media termination instance. The phone proxy uses this address for SRTP and RTP. For the media termination instance, you can configure a global media-termination address for all interfaces or configure a media-termination address for different interfaces. However, you cannot use a global media-termination address and media-termination addresses configured for each interface at the same time. If you configure a media termination address for multiple interfaces, you must configure an address on each interface that the ASA uses when communicating with IP phones. The IP addresses are publicly routable addresses that are unused IP addresses within the address range on that interface. See Media Termination Instance Prerequisites for the complete list of prerequisites that you must follow when creating the media termination instance and configuring the media termination addresses. |
Step 3 |
(Optional)
hostname(config-media-termination)#
rtp-min-port
port1
rtp-max-port
port2
hostname(config-media-termination)# rtp-min-port 2001 rtp-maxport 32770
|
Specifies the minimum and maximum values for the RTP port range for the media termination instance. Where port1 and port2 can be a value from 1024 to 65535. |
What To Do Next
Once you have created the media termination instance, create the phone proxy instance. See Creating the Phone Proxy Instance.
Creating the Phone Proxy Instance
Create the phone proxy instance.
Prerequisites
You must have already created the CTL file and TLS proxy instance for the phone proxy.
See Creating the CTL File and Creating the TLS Proxy Instance for a Non-secure Cisco UCM Cluster
|
|
|
Step 1 |
hostname(config)#
phone-proxy
phone_proxy_name
hostname(config)# phone-proxy myphoneproxy
|
Creates the phone proxy instance. Only one phone proxy instance can be configured on the security appliance. |
Step 2 |
hostname(config-phone-proxy)#
media-termination
instance_name
hostname(config-phone-proxy)# media-termination my_mt
|
Specifies the media termination instance used by the phone proxy for SRTP and RTP. Note You must create the media termination instance before you specify it in the phone proxy instance. See Creating the Media Termination Instance for the steps to create the media termination instance. |
Step 3 |
hostname(config-phone-proxy)#
tftp-server address
ip_address
interface
interface
hostname(config-phone-proxy)# tftp-server address 192.0.2.101 interface inside
|
Creates the TFTP server using the actual internal address and specify the interface on which the TFTP server resides. |
Step 4 |
hostame(config-phone-proxy)#
tls-proxy
proxy_name
hostame(config-phone-proxy)# tls-proxy mytls
|
Configures the TLS proxy instance that you have already created. |
Step 5 |
hostname(config-phone-proxy)#
ctl-file
ctl_name
hostame(config-phone-proxy)# ctl-file myctl
|
Configures the CTL file instance that you have already created, |
Step 6 |
hostname(config-phone-proxy)#
proxy-server
address
ip_address [
listen_port ]
interface
ifc
hostname(config-phone-proxy)# proxy-server 192.168.1.2 interface inside
|
(Optional) If the operational environment has an external HTTP proxy to which the IP phones direct all HTTP request, configures a proxy server. You can configure only one proxy server while the phone proxy is in use. By default, the Phone URL Parameters configured under the Enterprise Parameters use an FQDN in the URLs. The parameters might need to be changed to use an IP address if the DNS lookup for the HTTP proxy does not resolve the FQDNs. Note If the IP phones have already downloaded their configuration files after you have configured the proxy server, you must restart the IP phones so that they get the configuration file with the proxy server address in the file. |
Step 7 |
hostname(config-phone-proxy)#
cipc security-mode authenticated
|
(Optional) Forces Cisco IP Communicator (CIPC) softphones to operate in authenticated mode when CIPC softphones are deployed in a voice and data VLAN scenario. See Cisco IP Communicator Prerequisites for all requirements for using the phone proxy with CIPC. |
Step 8 |
hostname(config-phone-proxy)#
no disable service-settings
|
(Optional) Preserve the settings configured on the Cisco UCM for each IP phone configured. By default, the following settings are disabled on the IP phones:
- PC Port
- Gratuitous ARP
- Voice VLAN access
- Web Access
- Span to PC Port
|
What to Do Next
Once you have created the phone proxy instance, configuring SIP and Skinny for the phone proxy. See Enabling the Phone Proxy with SIP and Skinny Inspection.
Enabling the Phone Proxy with SIP and Skinny Inspection
Enables the phone proxy instance that you created to inspect SIP and Skinny protocol traffic.
Prerequisites
You must have already created the phone proxy instance. See Creating the Phone Proxy Instance.
|
|
|
Step 1 |
hostname(config)#
class-map
class_map_name
|
Configures the secure Skinny class of traffic to inspect. Traffic between the Cisco Unified Communications Manager and Cisco IP Phones uses SCCP and is handled by SCCP inspection. Where class_map_name is the name of the Skinny class map. |
Step 2 |
hostname(config-cmap)#
match port tcp
eq
2443
|
Matches the TCP port 2443 to which you want to apply actions for secure Skinny inspection. |
Step 3 |
hostname(config-cmap)#
exit
|
Exits from the Class Map configuration mode. |
Step 4 |
hostname(config)#
class-map
class_map_name
|
Configures the secure SIP class of traffic to inspect. Where class_map_name is the name of the SIP class map. |
Step 5 |
hostname(config-cmap)#
match port tcp
eq
5061
|
Matches the TCP port 5061 to which you want to apply actions for secure SIP inspection |
Step 6 |
hostname(config-cmap)#
exit
|
Exits from the Class Map configuration mode. |
Step 7 |
hostname(config)#
policy-map
name
|
Configure the policy map and attach the action to the class of traffic. |
Step 8 |
hostname(config-pmap)#
class
classmap-name
|
Assigns a class map to the policy map so that you can assign actions to the class map traffic. Where classmap_name is the name of the Skinny class map. |
Step 9 |
hostname(config-pmap-c)#
inspect skinny phone-proxy
pp_name
inspect skinny phone-proxy mypp
|
Enables SCCP (Skinny) application inspection and enables the phone proxy for the specified inspection session. |
Step 10 |
hostnae(config-pmap)#
class
classmap-name
|
Assigns a class map to the policy map so that you can assign actions to the class map traffic. Where classmap_name is the name of the SIP class map. |
Step 11 |
hostname(config-pmap-c)#
inspect sip phone-proxy
pp_name
inspect sip phone-proxy mypp
|
Enables SIP application inspection and enables the phone proxy for the specified inspection session. |
Step 12 |
hostname(config-pmap-c)#
exit
|
Exits from Policy Map configuration mode. |
Step 13 |
hostname(config)#
service-policy
policymap_name
interface
intf
service-policy pp_policy interface outside
|
Enables the service policy on the outside interface. |
Configuring Linksys Routers with UDP Port Forwarding for the Phone Proxy
When IP phones are behind a NAT-capable router, the router can be configured to forward the UDP ports to the IP address of the IP phone. Specifically, configure the router for UDP port forwarding when an IP phone is failing during TFTP requests and the failure is due to the router dropping incoming TFTP data packets. Configure the router to enable UDP port forwarding on port 69 to the IP phone.
As an alternative of explicit UDP forwarding, some Cable/DSL routers require you to designate the IP phone as a DMZ host. For Cable/DSL routers, this host is a special host that receives all incoming connections from the public network.
When configuring the phone proxy, there is no functional difference between an IP phone that has UDP ports explicitly forwarded or an IP phone designated as a DMZ host. The choice is entirely dependent upon the capabilities and preference of the end user.
Configuring Your Router
Your firewall/router needs to be configured to forward a range of UDP ports to the IP phone. This will allow the IP phone to receive audio when you make/receive calls.
Note Different Cable/DSL routers have different procedures for this configuration. Furthermore most NAT-capable routers will only allow a given port range to be forwarded to a single IP address
The configuration of each brand/model of firewall/router is different, but the task is the same. For specific instructions for your brand and model of router, please contact the manufacturer’s website.
Linksys Routers
Step 1 From your web browser, connect to the router administrative web page. For Linksys, this is typically something like http://192.168.1.1
.
Step 2 Click Applications & Gaming or the Port Forwarding tab (whichever is present on your router).
Step 3 Locate the table containing the port forwarding data and add an entry containing the following values:
Table 48-3 Port Forwarding Values to Add to Router
|
|
|
|
|
|
IP phone |
1024 |
65535 |
UDP |
Phone IP address |
Checked |
TFTP |
69 |
69 |
UDP |
Phone IP address |
Checked |
Step 4 Click Save Settings. Port forwarding is configured.
Troubleshooting the Phone Proxy
This section includes the following topics:
Debugging Information from the Security Appliance
This section describes how to use the debug, capture, and show commands to obtain debugging information for the phone proxy. See the command reference for detailed information about the syntax for these commands.
Table 48-4 lists the debug commands to use with the phone proxy.
Table 48-4 Security Appliance Debug Commands to Use with the Phone Proxy
|
|
|
To show error and event messages for TLS proxy inspection. |
debug inspect tls-proxy [ events | errors ] |
Use this command when your IP phone has successfully downloaded all TFTP files but is failing to complete the TLS handshake with the TLS proxy configured for the phone proxy. |
To show error and event messages of media sessions for SIP and Skinny inspections related to the phone proxy. |
debug phone-proxy media [ events | errors ] |
Use this command in conjunction with the debug sip command and the debug skinny command if your IP phone is experiencing call failures or audio problems. |
To show error and event messages of signaling sessions for SIP and Skinny inspections related to the phone proxy. |
debug phone-proxy signaling [ events | errors ] |
Use this command in conjunction with the debug sip command and the debug skinny command if your IP phone is failing to register with the Cisco UCM or if you are experiencing call failure. |
To show error and event messages of TFTP inspection, including creation of the CTL file and configuration file parsing. |
debug phone-proxy tftp [ events | errors ] |
|
To show debug messages for SIP application inspection. |
debug sip |
Use this command when your IP phones are experiencing connection problems; for example, you can connect within the network but cannot make calls off the network. In the output, check for 4XX or 5XX messages. |
To show debug messages for SCCP (Skinny) application inspection. |
debug skinny |
Use this command when your IP phones are experiencing connection problems; for example, you can connect within the network but cannot make calls off the network. In the output, check for 4XX or 5XX messages. |
Table 48-5 lists the capture commands to use with the phone proxy. Use the capture command on the appropriate interfaces (IP phones and Cisco UCM) to enable packet capture capabilities for packet sniffing and network fault isolation.
Table 48-5 Security Appliance Capture Commands to Use with the Phone Proxy
|
|
|
To capture packets on the ASA interfaces. |
capture capture_name interface interface_name |
Use this command if you are experiencing any problems that might require looking into the packets. For example, if there is a TFTP failure and the output from the debug command does not indicate the problem clearly, run the capture command on the interface on which the IP phone resides and the interface on which the TFTP server resides to see the transaction and where the problem could be. |
To capture data from the TLS proxy when there is a non-secure IP phone connecting to the phone proxy on the inside interface. |
capture capture_name packet-length bytes interface inside buffer buf_size |
|
To capture encrypted data from the TLS proxy when there are secure IP phones connecting to the phone proxy on the inside interface. |
capture capture_name type tls-proxy buffer buf_size packet-length bytes interface inside |
|
To capture encrypted inbound and outbound data from the TLS proxy on one or more interfaces. |
capture capture_name type tls-proxy buffer buf_size packet-length bytes interface interface_nam e |
If signaling fails, you might require capturing decrypted packets to see the contents of the SIP and SCCP signaling message. Use the type tls-proxy option in the capture command. |
Table 48-6 lists the show commands to use with the phone proxy.
Table 48-6 Security Appliance Show Commands to Use with the Phone Proxy
|
|
|
To show the packets or connections dropped by the accelerated security path. |
show asp drop |
Use this command to troubleshoot audio quality issues with the IP phones or other traffic issues with the phone proxy. In addition to running this command, get call status from the phone to check for any dropped packets or jitter. See Debugging Information from IP Phones. |
To show the classifier contents of the accelerated security path for the specific classifier domain. |
show asp table classify domain domain_name |
If the IP phones are not downloading TFTP files, use this command to check that the classification rule for the domain inspect-phone-proxy is set for hosts to the configured TFTP server under the phone proxy instance. If the IP phones are failing to register, use this command to make sure there is a classification rule for the domain app-redirect set for the IP phones that cannot register. |
To show the connections that are to the ASA or from the ASA, in addition to through-traffic connections. |
show conn all |
If you are experiencing problems with audio, use this command to make sure that there are connections opened from the IP phone to the media termination address.
UDP out 64.169.58.181:9014 in 192.168.200.101:39420 idle 0:01:51 bytes 522 flags p
Using this command shows that the phone proxy has connections that are going through “inspect-phone-proxy”, which inspects TFTP connections. Using this command verifies that the TFTP requests are being inspected because the p flag is there. |
To show the logs in the buffer and logging settings. |
show logging |
Before entering the show logging command, enable the logging buffered command so that the show logging command displays the current message buffer and the current settings. Use this command to determine if the phone proxy and IP phones are successfully completing the TLS handshake. Note Using the show logging command is useful for troubleshooting many problems where packets might be denied or there are translation failures. |
To show the corresponding media sessions stored by the phone proxy. |
show phone-proxy media-sessions |
Use this command to display output from successful calls. Additionally, use this command to troubleshoot problems with IP phone audio, such as one-way audio. |
To show the IP phones capable of Secure mode stored in the database. |
show phone-proxy secure-phones |
For any problems, make sure there is an entry for the IP phone in this output and that the port for this IP phone is non-zero, which indicates that it has successfully registered with the Cisco UCM. |
To show the corresponding signaling sessions stored by the phone proxy. |
show phone-proxy signaling-sessions |
Use this command to troubleshoot media or signaling failure. |
To show the configured service policies. |
show service-policy |
Use this command to show statistics for the service policy. |
To show active TLS proxy sessions related to the phone proxy. |
show tls-proxy sessions |
If the IP phone has failed to register, use this command to see if the IP phone has successfully completed the handshake with the TLS proxy configured for the phone proxy. |
Debugging Information from IP Phones
On the IP phone, perform the following actions:
- Check the Status messages on the IP phone by selecting the Settings button > Status > Status Messages and selecting the status item that you want to view.
- Collect the call-statistics data from the IP phone by selecting the Settings button > Status > Call Statistic. Data like the following displays:
RxType: G.729 TxType: G.729
RxSize: 20 ms TxSize: 20 ms
RxDisc: 0000 RxLost: 014001
- Check the Security settings on the IP phone by selecting the Settings button > Security Configuration. Settings for web access, Security mode, MIC, LSC, CTL file, trust list, and CAPF appear. Under Security mode, make sure the IP phone is set to Encrypted.
- Check the IP phone to determine which certificates are installed on the phone by selecting the Settings button > Security Configuration > Trust List. In the trustlist, verify the following:
– Make sure that there is an entry for each entity that the IP phone will need to contact. If there is a primary and backup Cisco UCM, the trustlist should contain entries for each Cisco UCM.
– If the IP phone needs an LSC, the record entry should contain a CAPF entry.
– Make sure that the IP addresses listed for each entry are the mapped IP addresses of the entities that the IP phone can reach.
- Open a web browser and access the IP phone console logs at the URL
http://
IP_phone_IP address. The device information appears in the page. In the Device Logs section in the left pane, click Console Logs.
IP Phone Registration Failure
The following errors can make IP phones unable to register with the phone proxy:
TFTP Auth Error Displays on IP Phone Console
Problem The IP phone displays the following Status message:
Solution This Status message can indicate a problem with the IP phone CTL file.
To correct problems with the IP phone CTL file, perform the following:
Step 1 From the IP phone, select the Setting button > Security Configuration > Trust List. Verify that each entity in the network—Primary Cisco UCM, Secondary Cisco UCM, TFTP server—has its own entry in the trustlist and that each entity IP address is reachable by the IP phone.
Step 2 From the ASA, verify that the CTL file for the phone proxy contains one record entry for each entity in the network—Primary Cisco UCM, Secondary Cisco UCM, TFTP server—by entering the following command:
hostname# show running-config all ctl-file [ctl_name]
Each of these record entries creates one entry on the IP phone trustlist. The phone proxy creates one entry internally with the function CUCM+TFTP.
Step 3 In the CTL file, verify that each IP address is the global or mapped IP address of the entity. If the IP phones are on multiple interfaces, additional addressing requirements apply. See Prerequisites for IP Phones on Multiple Interfaces.
Configuration File Parsing Error
Problem When the ASA receives the configuration file from the Cisco UCM and tries to parse it, the following error appears in the debug output ( debug phone-proxy tftp errors):
PP: 192.168.10.5/49357 requesting SEP00010002003.cnf.xml.sgn
PP: Beginning of element tag is missing, got !
PP: error parsing config file
PP: Error modifying config file, dropping packet
Solution Perform the following actions to troubleshoot this problem:
Step 1 Enter the following URL in a web browser to obtain the IP phone configuration file from the Cisco Unified CM Administration console:
http://<cucm_ip>:6970/<config_file_name>
For example, if the Cisco UCM IP address is 128.106.254.2 and the IP phone configuration file name is SEP000100020003.cnf.xml, enter:
http://128.106.254.2:6970/SEP000100020003.cnf.xml
Step 2 Save this file, open a case with TAC and send them this file and the output from running the debug phone-proxy tftp command on the ASA.
Configuration File Parsing Error: Unable to Get DNS Response
Problem When the ASA receives the configuration file from the Cisco UCM and tries to parse it, the following error appears in the debug output ( debug phone-proxy tftp errors):
PP: 192.168.10.5/49357 requesting SEP00010002003.cnf.xml.sgn
PP: Callback required for parsing config file
PP: Unable to get dns response for id 7
PP: Callback, error modifying config file
The error indicates that the Cisco UCM is configured as an FQDN and the phone proxy is trying to do a DNS lookup but failed to get a response.
Solution
Step 1 Verify that DNS lookup is configured on the ASA.
Step 2 If DNS lookup is configured, determine whether you can ping the FQDN for the Cisco UCM from the ASA.
Step 3 If ASA cannot ping the Cisco UCM FQDN, check to see if there is a problem with the DNS server.
Step 4 Additionally, use the name command to associate a name with an IP address with the FQDN. See the command reference for information about using the name command.
Non-configuration File Parsing Error
Problem The ASA receives a file other than an IP phone configuration file from the Cisco UCM and attempts to parse it. The following error appears in the debug output ( debug phone-proxy tftp):
PP: 192.168.10.5/49357 requesting SK72f64050-7ad5-4b47-9bfa-5e9ad9cd4aa9.xml.sgn
PP: Beginning of element tag is missing, got !
PP: error parsing config file
PP: Error modifying config file, dropping packet
Solution The phone proxy should parse only the IP phone configuration file. When the phone proxy TFTP state gets out of state, the phone proxy cannot detect when it is attempting to parse a file other than the IP phone configuration file and the error above appears in the ASA output from the debug phone-proxy tftp command.
Perform the following actions to troubleshoot this problem:
Step 1 Reboot the IP phone.
Step 2 On the ASA, enter the following command to obtain the error information from the first TFTP request to the point where the first error occurred.
hostname# debug phone-proxy tftp
Step 3 Capture the packets from the IP phone to the ASA. Make sure to capture the packets on the interface facing the IP phone and the interface facing the Cisco UCM. See Debugging Information from the Security Appliance.
Step 4 Save this troubleshooting data, open a case with TAC and give them this information.
Cisco UCM Does Not Respond to TFTP Request for Configuration File
Problem When the ASA forwards the TFTP request to the Cisco UCM for the IP phone configuration file, the Cisco UCM does not respond and the following errors appear in the debug output ( debug phone-proxy tftp):
PP: 192.168.10.5/49355 requesting SEP001562106AF3.cnf.xml.sgn
PP: 192.168.10.5/49355 requesting SEP001562106AF3.cnf.xml.sgn
PP: Client outside:192.168.10.5/49355 retransmitting request for Config file SEP001562106AF3.cnf.xml.sgn
PP: 192.168.10.5/49355 requesting SEP001562106AF3.cnf.xml.sgn
PP: Client outside:192.168.10.5/49355 retransmitting request for Config file SEP001562106AF3.cnf.xml.sgn
PP: 192.168.10.5/49355 requesting SEP001562106AF3.cnf.xml.sgn
PP: Client outside:192.168.10.5/49355 retransmitting request for Config file SEP001562106AF3.cnf.xml.sgn
Solution Perform the following actions to troubleshoot this problem:
Step 1 Determine why the Cisco UCM is not responding to the TFTP request by performing the following troubleshooting actions:
- Use the Cisco UCM to ping the ASA inside interface when PAT is configured for the outside interface so that the IP phone IP address is uses NAT for the ASA inside interface IP address.
- Use the Cisco UCM to ping the IP phone IP address when NAT and PAT are not configured.
Step 2 Verify that the ASA is forwarding the TFTP request. Capture the packets on the interface between the ASA and Cisco UCM. See Debugging Information from the Security Appliance.
IP Phone Does Not Respond After the Security Appliance Sends TFTP Data
Problem When the ASA receives a TFTP request from the IP phone for the CTL file and forwards the data to the IP phone, the phone might not see the data and the TFTP transaction fails.
The following errors appear in the debug output ( debug phone-proxy tftp):
PP: Client outside:68.207.118.9/33606 retransmitting request for CTL file CTLSEP001DA2B78E91.tlv
PP: Data Block 1 forwarded from 168.215.146.220/20168 to 68.207.118.9/33606 ingress ifc outside
PP: 68.207.118.9/33606 requesting CTLSEP001DA2B78E91.tlv
PP: Client outside:68.207.118.9/33606 retransmitting request for CTL file CTLSEP001DA2B78E91.tlv
PP: 68.207.118.9/33606 requesting CTLSEP001DA2B78E91.tlv
PP: Client outside:68.207.118.9/33606 retransmitting request for CTL file CTLSEP001DA2B78E91.tlv
Solution Perform the following actions to determine why the IP phone is not responding and to troubleshoot the problem:
Step 1 Verify that the ASA is forwarding the TFTP request by entering the following command to capture the packets on the interface between the ASA and the IP phone:
hostname# capture out interface outside
See the command reference for more information about using the capture command.
Step 2 If the IP phone is behind a router, the router might be dropping the data. Make sure UDP port forwarding is enabled on the router.
Step 3 If the router is a Linksys router, see Configuring Linksys Routers with UDP Port Forwarding for the Phone Proxy for information on the configuration requirements.
IP Phone Requesting Unsigned File Error
Problem The IP phone should always request a signed file. Therefore, the TFTP file being requested always has the.SGN extension.
When the IP phone does not request a signed file, the following error appears in the debug output ( debug phone-proxy tftp errors):
Error: phone requesting for unsigned config file
Solution Most likely, this error occurs because the IP phone has not successfully installed the CTL file from the ASA.
Determine whether the IP phone has successfully downloaded and installed the CTL file from the ASA by checking the Status messages on the IP phone. See Debugging Information from IP Phones for information.
IP Phone Unable to Download CTL File
Problem The IP phone Status message indicates it cannot download its CTL file and the IP phone cannot be converted to Secure (encrypted) mode.
Solution If the IP phone did not have an existing CTL file, check the Status messages by selecting the Settings button > Status > Status Messages. If the list contains a Status message indicating the IP phone encountered a CTL File Auth error, obtain the IP phone console logs, open a TAC case, and send them the logs.
Solution This error can appear in the IP phone Status messages when the IP phone already has an existing CTL file.
Step 1 Check the IP phone to see if a CTL file already exists on it. This can occur if the IP phone previously registered with a mixed mode cluster Cisco UCM. On the IP phone, select the Settings button > Security Configuration > CTL file.
Step 2 Erase the existing CTL file by selecting the Settings button > Security Configuration > CTL file > Select. Press **# on the keypad and select Erase.
Solution Problems downloading the CTL file might be caused by issues with media termination. Enter the following command to determine if the media-termination address in the phone proxy configuration is set correctly:
hostname(config)# show running-config all phone-proxy
media-termination address 10.10.0.25
cipc security-mode authenticated
timeout secure-phones 0:05:00
Make sure that each media-termination instance is created correctly and that the address or addresses are set correctly. The ASA must meet specific criteria for media termination. See Media Termination Instance Prerequisites for the complete list of prerequisites that you must follow when creating the media termination instance and configuring the media termination addresses.
IP Phone Registration Failure from Signaling Connections
Problem The IP phone is unable to complete the TLS handshake with the phone proxy and download its files using TFTP.
Solution
Step 1 Determine if the TLS handshake is occurring between the phone proxy and the IP phone, perform the following:
a. Enable logging with the following command:
hostname(config)# logging buffered debugging
b. To check the output from the syslogs captured by the logging buffered command, enter the following command:
The syslogs will contain information showing when the IP phone is attempting the TLS handshake, which happens after the IP phone downloads its configuration file.
Step 2 Determine if the TLS proxy is configured correctly for the phone proxy:
a. Display all currently running TLS proxy configurations by entering the following command:
hostname# show running-config tls-proxy
server trust-point _internal_PP_<ctl_file_instance_name>
client ldc issuer ldc_signer
client ldc key-pair phone_common
b. Verify that the output contains the server trust-point command under the tls-proxy command (as shown in substep a.).
If you are missing the server trust-point command, modify the TLS proxy in the phone proxy configuration.
See Step 3 in the “Task Flow for Configuring the Phone Proxy in a Non-secure Cisco UCM Cluster” section, or Step 3 in the “Task Flow for Configuring the Phone Proxy in a Mixed-mode Cisco UCM Cluster” section.
Having this command missing from the TLS proxy configuration for the phone proxy will cause TLS handshake failure.
Step 3 Verify that all required certificates are imported into the ASA so that the TLS handshake will succeed.
a. Determine which certificates are installed on the ASA by entering the following command:
hostname# show running-config crypto
Additionally, determine which certificates are installed on the IP phones. See Debugging Information from IP Phones for information about checking the IP phone to determine if it has MIC installed on it.
b. Verify that the list of installed certificates contains all required certificates for the phone proxy.
See Table 48-2 , Certificates Required by the Security Appliance for the Phone Proxy , for information.
c. Import any missing certificates onto the ASA. See also Importing Certificates from the Cisco UCM.
Step 4 If the steps above fail to resolve the issue, perform the following actions to obtain additional troubleshooting information for Cisco Support.
a. Enter the following commands to capture additional debugging information for the phone proxy:
hostname# debug inspect tls-proxy error
hostname# show running-config ssl
hostname(config) show tls-proxy tls_name session host host_addr detail
b. Enable the capture command on the inside and outside interfaces (IP phones and Cisco UCM) to enable packet capture capabilities for packet sniffing and network fault isolation. See the command reference for information.
Problem The TLS handshake succeeds, but signaling connections are failing.
Solution Perform the following actions:
- Check to see if SIP and Skinny signaling is successful by using the following commands:
– debug sip
– debug skinny
- If the TLS handshake is failing and you receive the following syslog, the SSL encryption method might not be set correctly:
%ASA-6-725001: Starting SSL handshake with client dmz:171.169.0.2/53097 for TLSv1 session.
%ASA-7-725010: Device supports the following 1 cipher(s).
%ASA-7-725011: Cipher[1] : RC4-SHA
%ASA-7-725008: SSL client dmz:171.169.0.2/53097 proposes the following 2 cipher(s).
%ASA-7-725011: Cipher[1] : AES256-SHA
%ASA-7-725011: Cipher[2] : AES128-SHA
%ASA-7-725014: SSL lib error. Function: SSL3_GET_CLIENT_HELLO Reason: no shared cipher
%ASA-6-725006: Device failed SSL handshake with dmz client:171.169.0.2/53097
Set the correct ciphers by completing the following procedure:
Step 1 To see the ciphers being used by the phone proxy, enter the following command:
hostname# show run all ssl
Step 2 To add the required ciphers, enter the following command:
hostname(config)# ssl encryption
The default is to have all algorithms available in the following order:
[3des-sha1] [des-sha1] [rc4-md5] [possibly others]
See the command reference for more information about setting ciphers with the ssl encryption command.
SSL Handshake Failure
Problem The phone proxy is not functioning. Initial troubleshooting uncovered the following errors in the ASA syslogs:
%ASA-7-725014: SSL lib error. Function: SSL3_READ_BYTES Reason: ssl handshake failure
%ASA-7-725014: SSL lib error. Function: SSL3_GET_CLIENT_CERTIFICATE Reason: no certificate returned
%ASA-6-725006: Device failed SSL handshake with outside client:72.146.123.158/30519
%ASA-3-717009: Certificate validation failed. No suitable trustpoints found to validate certificate serial number: 62D06172000000143FCC, subject name: cn=CP-7962G-SEP002155554502,ou=EVVBU,o=Cisco Systems Inc.
%ASA-3-717027: Certificate chain failed validation. No suitable trustpoint was found to validate chain.
Solution
Verify that all required certificates are imported into the ASA so that the TLS handshake will succeed.
Step 1 Determine which certificates are installed on the ASA by entering the following command:
hostname# show running-config crypto
Additionally, determine which certificates are installed on the IP phones. See Debugging Information from IP Phones for information about checking the IP phone to determine if it has MIC installed on it.
Step 2 Verify that the list of installed certificates contains all required certificates for the phone proxy.
See Table 48-2 , Certificates Required by the Security Appliance for the Phone Proxy , for information.
Step 3 Import any missing certificates onto the ASA. See also Importing Certificates from the Cisco UCM.
Problem The phone proxy is not functioning. Initial troubleshooting uncovered the following errors in the ASA syslogs:
%ASA-6-725001: Starting SSL handshake with client dmz:171.169.0.2/53097 for TLSv1 session.
%ASA-7-725010: Device supports the following 1 cipher(s).
%ASA-7-725011: Cipher[1] : RC4-SHA
%ASA-7-725008: SSL client dmz:171.169.0.2/53097 proposes the following 2 cipher(s).
%ASA-7-725011: Cipher[1] : AES256-SHA
%ASA-7-725011: Cipher[2] : AES128-SHA
%ASA-7-725014: SSL lib error. Function: SSL3_GET_CLIENT_HELLO Reason: no shared cipher
%ASA-6-725006: Device failed SSL handshake with dmz client:171.169.0.2/53097
Solution the SSL encryption method might not be set correctly. Set the correct ciphers by completing the following procedure:
Step 1 To see the ciphers being used by the phone proxy, enter the following command:
hostname# show run all ssl
Step 2 To add the required ciphers, enter the following command:
hostname(config)# ssl encryption
The default is to have all algorithms available in the following order:
[3des-sha1] [des-sha1] [rc4-md5] [possibly others]
See the command reference for more information about setting ciphers with the ssl encryption command.
Certificate Validation Errors
Problem Errors in the ASA log indicate that certificate validation errors occurred.
Entering the show logging asdm command, displayed the following errors:
3|Jun 19 2008 17:23:54|717009: Certificate validation failed. No suitable trustpoints found to validate
certificate serial number: 348FD2760000000E6E27, subject name: cn=CP-7961G-SEP001819A89CC3,ou=EVVBU,o=Cisco Systems Inc.
Solution
In order for the phone proxy to authenticate the MIC provided by the IP phone, it needs the Cisco Manufacturing CA (MIC) certificate imported into the ASA.
Verify that all required certificates are imported into the ASA so that the TLS handshake will succeed.
Step 1 Determine which certificates are installed on the ASA by entering the following command:
hostname# show running-config crypto
Additionally, determine which certificates are installed on the IP phones. The certificate information is shown under the Security Configuration menu. See Debugging Information from IP Phones for information about checking the IP phone to determine if it has the MIC installed on it.
Step 2 Verify that the list of installed certificates contains all required certificates for the phone proxy.
See Table 48-2 , Certificates Required by the Security Appliance for the Phone Proxy , for information.
Step 3 Import any missing certificates onto the ASA. See also Importing Certificates from the Cisco UCM.
Media Termination Address Errors
Problem Entering the media-termination address command displays the following errors:
hostname(config-phone-proxy)# media-termination address ip_address
ERROR: Failed to apply IP address to interface Virtual254, as the network overlaps with interface GigabitEthernet0/0. Two interfaces cannot be in the same subnet.
ERROR: Failed to set IP address for the Virtual interface
ERROR: Could not bring up Phone proxy media termination interface
ERROR: Failed to find the HWIDB for the Virtual interface
Solution Enter the following command to determine if the media-termination address in the phone proxy configuration is set correctly:
hostname(config)# show running-config all phone-proxy
asa2(config)# show running-config all phone-proxy
media-termination address 10.10.0.25
cipc security-mode authenticated
timeout secure-phones 0:05:00
Make sure that each media-termination instance is created correctly and that the address or addresses are set correctly. The ASA must meet specific criteria for media termination. See Media Termination Instance Prerequisites for the complete list of prerequisites that you must follow when creating the media termination instance and configuring the media termination addresses.
Audio Problems with IP Phones
The following audio errors can occur when the IP phones connecting through the phone proxy.
Media Failure for a Voice Call
Problem The call signaling completes but there is one way audio or no audio.
Solution
- Problems with one way or no audio might be caused by issues with media termination. Enter the following command to determine if the media-termination address in the phone proxy configuration is set correctly:
hostname(config)# show running-config all phone-proxy
asa2(config)# show running-config all phone-proxy
media-termination address 10.10.0.25
cipc security-mode authenticated
timeout secure-phones 0:05:00
- Make sure that each media-termination instance is created correctly and that the address or addresses are set correctly. The ASA must meet specific criteria for media termination. See Media Termination Instance Prerequisites for the complete list of prerequisites that you must follow when creating the media termination instance and configuring the media termination addresses.
- If each media-termination address meets the requirements, determine whether the IP addresses are reachable by all IP phones.
- If each IP address is set correctly and reachable by all IP phones, check the call statistics on an IP phone (see Debugging Information from IP Phones) and determine if there are Rcvr packets and Sender packets on the IP phone, or if there are any Rcvr Lost or Discarded packets.
Saving SAST Keys
Site Administrator Security Token (SAST) keys on the ASA can be saved in the event a recovery is required due to hardware failure and a replacement is required. The following steps shows how to recover the SAST keys and use them on the new hardware.
The SAST keys can be seen via the show crypto key mypubkey rsa command. The SAST keys are associated with a trustpoint that is labeled _internal_ ctl-file_name _SAST_ X where ctl-file-name is the name of the CTL file instance that was configured, and X is an integer from 0 to N-1 where N is the number of SASTs configured for the CTL file (the default is 2).
Step 1 On the ASA, export all the SAST keys in PKCS-12 format by using the crypto ca export command:
hostname(config)# crypto ca export _internal_ctl-file_name_SAST_X pkcs12 passphrase
hostname(config)# Exported pkcs12 follows:
MIIGZwIBAzCCBiEGCSqGSIb3DQEHAaCCBhIEggYOMIIGCjCCBgYGCSqGSIb3DQEH
MIIGZwIBAzCCBiEGCSqGSIb3DQEHAaCCBhIEggYOMIIGCjCCBgYGCSqGSIb3DQEH
---End - This line not part of the pkcs12---
hostname(config)# crypto ca export _internal_ctl-file_name_SAST_X pkcs12 passphrase
hostname(config)# Exported pkcs12 follows:
MIIGZwIBAzCCBiEGCSqGSIb3DQEHAaCCBhIEggYOMIIGCjCCBgYGCSqGSIb3DQEH
---End - This line not part of the pkcs12---
Note Save this output somewhere secure.
Step 2 Import the SAST keys to a new ASA.
a. To import the SAST key, enter the following command:
hostname(config)# crypto ca import trustpoint pkcs12 passphrase
Where trustpoint is _internal_ ctl-file_name _SAST_ X and ctl-file-name is the name of the CTL file instance that was configured, and X is an integer from 0 to 4 depending on what you exported from the ASA.
b. Using the PKCS-12 output you saved in Step 1, enter the following command and paste the output when prompted:
hostname(config)# crypto ca import _internal_ctl-file_name_SAST_X pkcs12 passphrase
hostname(config)# Enter the base 64 encoded pkcs12.
hostname(config)# End with the word "quit" on a line by itself:
MIIGZwIBAzCCBiEGCSqGSIb3DQEHAaCCBhIEggYOMIIGCjCCBgYGCSqGSIb3DQEH
INFO: Import PKCS12 operation completed successfully
hostname(config)# crypto ca import _internal_ctl-file_name_SAST_X pkcs12 passphrase
hostname(config)# Enter the base 64 encoded pkcs12.
hostname(config)# End with the word "quit" on a line by itself:
MIIGZwIBAzCCBiEGCSqGSIb3DQEHAaCCBhIEggYOMIIGCjCCBgYGCSqGSIb3DQEH
INFO: Import PKCS12 operation completed successfully
Step 3 Create the CTL file instance on the new ASA using the same name as the one used in the SAST trustpoints created in Step 2 by entering the following commands. Create trustpoints for each Cisco UMC (primary and secondary).
hostname(config)# ctl-file ctl_name
hostname(config-ctl-file)# record-entry cucm trustpoint trust_point address address
hostname(config-ctl-file)# record-entry capf trustpoint trust_point address address
hostname(config-ctl-file)# no shutdown
Configuration Examples for the Phone Proxy
This section includes the following topics:
Example 1: Nonsecure Cisco UCM cluster, Cisco UCM and TFTP Server on Publisher
Figure 48-2 shows an example of the configuration for a non-secure Cisco UCM cluster using the following topology.
Figure 48-2 Nonsecure Cisco UCM cluster, Cisco UCM and TFTP Server on Publisher
object network obj-192.0.2.101
nat (inside,outside) static 10.10.0.26
access-list pp extended permit udp any host 10.10.0.26 eq 69
access-group pp in interface outside
crypto key generate rsa label cucmtftp_kp modulus 1024
crypto ca trustpoint cucm_tftp_server
crypto ca enroll cucm_tftp_server
record-entry cucm-tftp trustpoint cucm_tftp_server address 10.10.0.26
server trust-point _internal_PP_myctl
media-termination my_mediaterm
address 192.0.2.25 interface inside
address 10.10.0.25 interface outside
media-termination my_mediaterm
tftp-server address 192.0.2.101 interface inside
inspect skinny phone-proxy mypp
inspect sip phone-proxy mypp
service-policy pp_policy interface outside
Example 2: Mixed-mode Cisco UCM cluster, Cisco UCM and TFTP Server on Publisher
Figure 48-3 shows an example of the configuration for a mixed-mode Cisco UCM cluster using the following topology.
Figure 48-3 Mixed-mode Cisco UCM cluster, Cisco UCM and TFTP Server on Publisher
object network obj-192.0.2.101
nat (inside,outside) static 10.10.0.26
access-list pp extended permit udp any host 10.10.0.26 eq 69
access-group pp in interface outside
crypto key generate rsa label cucmtftp_kp modulus 1024
crypto ca trustpoint cucm_tftp_server
crypto ca enroll cucm_tftp_server
record-entry cucm-tftp trustpoint cucm_tftp_server address 10.10.0.26
crypto key generate rsa label ldc_signer_key modulus 1024
crypto key generate rsa label phone_common modulus 1024
crypto ca trustpoint ldc_server
fqdn my-ldc-ca.exmaple.com
subject-name cn=FW_LDC_SIGNER_172_23_45_200
crypto ca enroll ldc_server
server trust-point _internal_PP_myctl
client ldc issuer ldc_server
client ldc keypair phone_common
client cipher-suite aes128-sha1 aes256-sha1
media-termination my_mediaterm
address 192.0.2.25 interface inside
address 10.10.0.25 interface outside
media-termination my_mediaterm
tftp-server address 192.0.2.101 interface inside
inspect skinny phone-proxy mypp
inspect sip phone-proxy mypp
service-policy pp_policy interface outside
Example 3: Mixed-mode Cisco UCM cluster, Cisco UCM and TFTP Server on Different Servers
Figure 48-4 shows an example of the configuration for a mixed-mode Cisco UCM cluster using the following topology where the TFTP server resides on a different server from the Cisco UCM.
In this sample, the static interface PAT for the TFTP server is configured to appear like the ASA’s outside interface IP address.
Figure 48-4 Mixed-mode Cisco UCM cluster, Cisco UCM and TFTP Server on Different Servers
object network obj-192.0.2.105
nat (inside,outside) static 10.10.0.26
object network obj-192.0.2.101
nat (inside,outside) static interface udp 69 69
access-list pp extended permit udp any host 10.10.0.24 eq 69
access-group pp in interface outside
crypto key generate rsa label cucm_kp modulus 1024
crypto ca trustpoint cucm
crypto key generate rsa label tftp_kp modulus 1024
crypto ca trustpoint tftp_server
crypto ca enroll tftp_server
record-entry cucm trustpoint cucm_server address 10.10.0.26
crypto key generate rsa label ldc_signer_key modulus 1024
crypto key generate rsa label phone_common modulus 1024
crypto ca trustpoint ldc_server
fqdn my-ldc-ca.exmaple.com
subject-name cn=FW_LDC_SIGNER_172_23_45_200
crypto ca enroll ldc_server
server trust-point _internal_PP_myctl
client ldc issuer ldc_server
client ldc keypair phone_common
client cipher-suite aes128-sha1 aes256-sha1
media-termination my_mediaterm
address 192.0.2.25 interface inside
address 10.10.0.25 interface outside
media-termination my_mediaterm
tftp-server address 192.0.2.101 interface inside
inspect skinny phone-proxy mypp
inspect sip phone-proxy mypp
service-policy pp_policy interface outside
Example 4: Mixed-mode Cisco UCM cluster, Primary Cisco UCM, Secondary and TFTP Server on Different Servers
Figure 48-5 shows an example of the configuration for a mixed-mode Cisco UCM cluster using the following topology where the TFTP server resides on a different server from the primary and secondary Cisco UCMs.
In this sample, the static interface PAT for the TFTP server is configured to appear like the ASA’s outside interface IP address.
Figure 48-5 Mixed-mode Cisco UCM cluster, Primary Cisco UCM, Secondary Cisco UCM, and TFTP Server on Different Servers
object network obj-192.0.2.105
nat (inside,outside) static 10.10.0.27
object network obj-192.0.2.101
nat (inside,outside) static interface udp 69 69
object network obj-192.0.2.106
nat (inside,outside) static 10.10.0.26
access-list pp extended permit udp any host 10.10.0.24 eq 69
access-group pp in interface outside
crypto key generate rsa label cluster_kp modulus 1024
crypto ca trustpoint pri_cucm
crypto ca enroll pri_cucm
crypto ca trustpoint sec_cucm
crypto ca enroll sec_cucm
crypto ca trustpoint tftp_server
crypto ca enroll tftp_server
record-entry tftp trustpoint tftp_server address 10.10.0.24
record-entry cucm trustpoint pri_cucm_server address 10.10.0.27
record-entry cucm trustpoint sec_cucm_server address 10.10.0.2
crypto key generate rsa label ldc_signer_key modulus 1024
crypto key generate rsa label phone_common modulus 1024
crypto ca trustpoint ldc_server
fqdn my-ldc-ca.exmaple.com
subject-name cn=FW_LDC_SIGNER_172_23_45_200
crypto ca enroll ldc_server
server trust-point _internal_PP_myctl
client ldc issuer ldc_server
client ldc keypair phone_common
client cipher-suite aes128-sha1 aes256-sha1
media-termination my_mediaterm
address 192.0.2.25 interface inside
address 10.10.0.25 interface outside
media-termination my_mediaterm
tftp-server address 192.0.2.101 interface inside
inspect skinny phone-proxy mypp
inspect sip phone-proxy mypp
service-policy pp_policy interface outside
Example 5: LSC Provisioning in Mixed-mode Cisco UCM cluster; Cisco UCM and TFTP Server on Publisher
Figure 48-6 shows an example of the configuration for a mixed-mode Cisco UCM cluster where LSC provisioning is required using the following topology.
Note Doing LSC provisioning for remote IP phones is not recommended because it requires that the IP phones first register and they have to register in nonsecure mode. Having the IP phones register in nonsecure mode requires the Administrator to open the nonsecure signaling port for SIP and SCCP on the ASA. If possible, LSC provisioning should be done inside the corporate network before giving the IP phones to the end-users.
In this sample, you create an access list to allow the IP phones to contact the TFTP server and to allow the IP phones to register in nonsecure mode by opening the nonsecure port for SIP and SCCP as well as the CAPF port for LSC provisioning.
Additionally, you create the CAPF trustpoint by copying and pasting the CAPF certificate from the Cisco UCM Certificate Management software.
Figure 48-6 LSC Provisioning in Mixed-mode Cisco UCM cluster; Cisco UCM and TFTP Server on Publisher
object network obj-192.0.2.105
nat (inside,outside) static 10.10.0.26
object network obj-192.0.2.101
nat (inside,outside) static interface udp 69 69
access-list pp extended permit udp any host 10.10.0.24 eq 69
access-list pp extended permit tcp any host 10.10.0.26 eq 2000
access-list pp extended permit tcp any host 10.10.0.26 eq 5060
access-list pp extended permit tcp any host 10.10.0.26 eq 3804
access-group pp in interface outside
crypto key generate rsa label cluster_kp modulus 1024
crypto ca trustpoint cucm
crypto ca trustpoint tftp_server
crypto ca enroll tftp_server
crypto ca trustpoint capf
crypto ca authenticate capf
record-entry cucm trustpoint cucm_server address 10.10.0.26
record-entry capf trustpoint capf address 10.10.0.26
crypto key generate rsa label ldc_signer_key modulus 1024
crypto key generate rsa label phone_common modulus 1024
crypto ca trustpoint ldc_server
fqdn my-ldc-ca.exmaple.com
subject-name cn=FW_LDC_SIGNER_172_23_45_200
crypto ca enroll ldc_server
server trust-point _internal_PP_myctl
client ldc issuer ldc_server
client ldc keypair phone_common
client cipher-suite aes128-sha1 aes256-sha1
media-termination my_mediaterm
address 192.0.2.25 interface inside
address 10.10.0.25 interface outside
media-termination my_mediaterm
tftp-server address 192.0.2.101 interface inside
inspect skinny phone-proxy mypp
inspect sip phone-proxy mypp
service-policy pp_policy interface outside
Example 6: VLAN Transversal
Figure 48-7 shows an example of the configuration to force Cisco IP Communicator (CIPC) softphones to operate in authenticated mode when CIPC softphones are deployed in a voice and data VLAN scenario. VLAN transversal is required between CIPC softphones on the data VLAN and hard phones on the voice VLAN.
In this sample, the Cisco UCM cluster mode is nonsecure.
In this sample, you create an access list to allow the IP phones to contact the TFTP server and to allow the IP phones to register in nonsecure mode by opening the nonsecure port for SIP and SCCP as well as the CAPF port for LSC provisioning.
In this sample, you configure NAT for the CIPC by using PAT so that each CIPC is mapped to an IP address space in the Voice VLAN.
Additionally, you create the CAPF trustpoint by copying and pasting the CAPF certificate from the Cisco UCM Certificate Management software.
Note Cisco IP Communicator supports authenticated mode only and does not support encrypted mode; therefore, there is no encrypted voice traffic (SRTP) flowing from the CIPC softphones.
Figure 48-7 VLAN Transversal Between CIPC Softphones on the Data VLAN and Hard Phones on the Voice VLAN
object network obj-10.130.50.0
subnet 10.130.50.0 255.255.255.0
nat (data,voice) dynamic 192.0.2.10
object network obj-10.130.50.5
nat (data,voice) static 192.0.2.101
access-list pp extended permit udp any host 10.130.50.5 eq 69
access-list pp extended permit tcp any host 10.130.50.5 eq 2000
access-list pp extended permit tcp any host 10.130.50.5 eq 5060
access-list pp extended permit tcp any host 10.130.50.5 eq 3804
access-group pp in interface data
crypto ca generate rsa label cucmtftp_kp modulus 1024
crypto ca trustpoint cucm_tftp_server
crypto ca enroll cucm_tftp_server
crypto ca trustpoint capf
crypto ca authenticate capf
record-entry cucm-tftp trustpoint cucm_tftp_server address 10.130.50.5
record-entry capf trustpoint capf address 10.130.50.5
server trust-point _internal_PP_myctl
media-termination my_mediaterm
media-termination my_mediaterm
tftp-server address 10.10.0.20 interface inside
cipc security-mode authenticated
inspect skinny phone-proxy mypp
inspect sip phone-proxy mypp
service-policy pp_policy interface data