Table Of Contents
Release Notes for Cisco Voice Switch Service Module (VXSM) Release 5.2
These release notes are part number OL-7089-01 Rev. A0, September 30, 2005.
The Voice Switch Service Module (VXSM) product is supported by the MGX 8880 Media Gateway and the MGX 8850 Multiservice Switch. Refer to their respective release notes for platform and version level support guidelines.
The VXSM software release notes are supported by the Cisco Voice Switch Services (VXSM) Configuration Guide, Release 5.2 and the Cisco Voice Switch Services (VXSM) Command Reference, Release 5.2, which are available on cisco.com.
Table of Contents
About Release 5.2
The VXSM Release 5.2 follows VXSM Release 5.0.70. 205
New Features in Release 5.2
Support For Packet Cable 1.1 Specification
PacketCable 1.1 specification defines the protocols and network interfaces required to provide IP voice services over cable networks. VXSM has been certified for PacketCable 1.1 compliance by CableLabs.
New MGX-VXSM-T3 Card Set
Release 5.2 introduces a third VXSM card set for the support of T3 lines. The card set consists of a six T3 port front card and a half height three T3 port back card. The front card can be configured with either a single back card or two back cards.
E911 Emergency Services
VXSM supports an emergency services feature in which 911 dialed emergency calls are automatically directed to an E911 Tandem switch and then onto a Public Safety Answering Point (PSAP).
Enhanced 911 (E911) is a Federal Communications Commission's (FCC) initiative introduced to increase public safety by the deployment of a nationwide, seamless communications system for emergency services that includes the provision of location information for wireless 911 calls.
The E911 feature on VXSM is implemented using TGCP MO package and is intended for use in packet cable applications.
Busy Line Verification and Operator Interruption (BLV/OI)
VXSM now supports BLV/OI through the MT package of the TGCP protocol under the control of a Call Agent. With this feature a caller can request that an operator check a called station to ascertain whether or not it is busy. This feature permits the operator to interrupt an ongoing call and relay a message to the called party.
Bearer and IP Security
VXSM provides a set of security features for the protection of both bearer and signaling traffic in switching VoIP applications using TGCP. In particular, these features are designed to meet PacketCable` standards.
RTP and RTCP bearer streams can be protected across an IP network through the use of encryption and authentication algorithms that are applied to the bearer payloads.
The specific security algorithms that are used for any particular call are negotiated during call setup between the two ends of the call with the Media Gateway Controller acting as a mediator in the process. The signaling links between the media gateways and the media gateway controllers are themselves protected using Internet Security (IPsec and IKE) protocols.
T.38 Fax Relay
VXSM Release 5.2 extends the support for voiceband traffic (fax, modem, TTY) by offering a T.38 Fax Relay feature as an alternative to the already supported Fax/Modem Passthrough feature.
In fax relay mode, the gateway demodulates the T.30 transmission received from the calling terminal. The facsimile control and the image data are transferred across the packet network using Internet Facsimile Protocol (IFP) packets, over the transport protocol (UDP). The T.38 Fax Relay feature can be configured for Call Agent controlled or Gateway controlled call setup.
The receiving gateway decodes the transferred information and establishes communication with the called facsimile terminal using normal T.30 procedures. The receiving gateway forwards all relevant responses from the called terminal to the emitting gateway.
In general, fax relay offers smaller bandwidth demands on the packet network and provides greater reliability in successful fax transmission when compared with the fax/modem passthrough method.
T.38 Fax Relay supports TGCP and MGCP call control protocols only.
For each VXSM card type (OC-3, T1/E1, or T3), two firmware images are available, namely, Non-CALEA and CALEA. At order time, the user must specify whether a Non-CALEA or CALEA image is required.
The Non-CALEA image supports three Media Gateway Call Control (MGC) protocols, namely, H.248, MGCP, and TGCP. However, the image supports only one protocol at a time. The user must choose between the H.248, MGCP, and TGCP versions when the image is first loaded from the PXM using the setrev command.
The CALEA image supports TGCP and MGCP only. The protocol must be explicitly selected when the image is loaded from the PXM using the setrev command.
Upgrading from an Earlier VXSM Release
VXSM can be gracefully upgraded (configuration is preserved) from VXSM Release 220.127.116.11 so long as the original and the upgraded images are of the same version (for example Non-CALEA, TGCP to Non-CALEA, TGCP). When loading or upgrading a boot or runtime image to a VXSM card, users must observe the following caution.
Caution Many of the commands involved in loading or upgrading boot and runtime images can take several minutes to execute completely. If the user resets or otherwise disturbs the VXSM card during a loading or upgrading process, the card can easily be damaged to the extent that it must be returned to the factory for repair.
THE REAPPEARANCE OF THE COMMAND PROMPT AFTER A COMMAND IS ENTERED DOES NOT INDICATE THAT THE IMAGE LOAD OR UPGRADE HAS BEEN COMPLETED.
After the execution of the burnboot, clrsmcnf, loadrev, or setrev commands, the user must execute either a dspcds or dsprev command periodically to verify that the state of the VXSM card being loaded or upgraded is either Active, Standby, or Failed.
ONLY WHEN THE CARD IS DISPLAYED TO BE IN ONE OF THESE STATES IS IT SAFE TO GO TO THE NEXT STEP.
A single VXSM card can be configured for either switching VoIP applications or AAL 2 trunking applications but not both. However, both applications can be supported in a single gateway by configuring some VXSM cards for switching VoIP and other VXSM cards for AAL 2 trunking.
Online Diagnostic feature as applied to VXSM.
The online diagnostics feature as implemented on the PXM45 card is supported on VXSM Release 5.2. When enabled, using the PXM45 cnfdiag command, this feature performs non-intrusive diagnostic tests that use four of the VXSM's DSP codecs.
If the user executes the VXSM dspdspcodecpools command, the resulting display shows the four codecs being used (for diagnostics) and subtracts them from the remaining available codecs (see example below).MGX8850.9.VXSM.a > dspdspcodecpools=============================================================DSP codec capacity usage=============================================================Codec pool Current utilized Current availablecapacity (#calls) capacity (#calls)========== ================= =================G711 family 4 8060G729/G726/T.38 family 0 4030
The online diagnostics feature does not reduce the maximum number of 8064 codecs available for calls on the VXSM card. If the number of call requests on the VXSM is sufficiently high, the online diagnostic feature is disabled automatically and the four codecs are made available for active calls.
DSP Resources under Mixed Codec Conditions
When the same codec is used to setup calls on the gateway the available DSP resources will be fully utilized. However when different codecs are used to setup calls the amount of utilizable DSP resources may be limited in certain cases due to fragmentation.
Fragmentation is said to have occurred when the available capacities on two different DSP resources have enough available capacity to support a call of a particular codec type but cannot support that codec type individually.
Consider two DSP resources whose available capacity is 1 unit each making the total available capacity 2 units. However a codec that requires 2 units cannot be supported in the system because the available capacities have been fragmented across the individual DSP resources.
The DSP allocation algorithm on VXSM does make an attempt to smooth the effects of fragmentation but towards the end, fragmentation could happen as the future pattern of calls cannot be predicted beforehand.
Configuring Switching and Trunking Applications
The simultaneous operation of mixed applications (Switched VoIP applications and Non-switched Trunking applications) is not supported on a VXSM card. However, both applications can be supported in the Media Gateway by using multiple VXSM cards.
VXSM Management Information Base
The VXSM Management Information Base (MIB) Version 5.2 is available by request through your Cisco VXSM product marketing representative.
Alternatively, users with CCO accounts can access the MIB and VXSM software on-line at:
The procedure is:
Step 1 Log on to http://www.cisco.com/kobayashi/sw-center/sw-wan.shtml
Step 2 Locate the VXSM platform (either VXSM 8880 or VXSM 8850) and click the down arrow to expand the "Select Release Level" drop down menu.
Step 3 Select the desired MIB release level (for example, Release 5200) to display a list of downloadable files.
Step 4 Click on the desired file (for example, mgx8850-fw-5200.tar).
Step 5 Read the license agreement and, if approved, click Accept..
Step 6 In the Software Download dialog box, click on Download: filename (where filename is the name of the file selected for download). This step starts the download procedure.
Step 7 Follow the normal file download procedure for your computer.
Step 8 When the file has been downloaded, untar or unzip the downloaded file. The MIB file is included in the downloaded file and is listed as a tar file (for example mgx8850rel5070mib.tar).
Step 9 Untar the MIB file to display its contents.
Service Module Support By Platform
Note VXSM Release 5.2 is only supported with PXM-45.
VXSM software interoperability with the MGX 8880 Media Gateway or the Cisco MGX 8850 (PXM45) Multiservice Switch platform software is listed in Table 1.
Table 2 describes the software images available for Release 5.2 for VXSM.
Caveats for VXSM Release 5.2
This section describes software caveats for Release 5.2
Open Caveats in Release 5.2
Table 3 describes the open caveats in VXSM Release 5.2
Resolved Caveats in Release 5.2
Table 4 describes the open caveats that existed in VXSM Release 18.104.22.168 or later and are now resolved in Release 5.2.
The MGX-VXSM-155 card is also known as the MGX-VXSM-4OC card.
The MGX-VXSM-T1/E1 card is also known as the MGX-VXSM-48T1/E1 card.
The MGX-VXSM-T3 card is also known as the MGX-VXSM-6T3 card.
The following documents contains information that may be useful to software Release 5.2 for VXSM:
•Cisco MGX 8850 (PXM1E/PXM45), Cisco MGX 8950, and Cisco MGX 8830 Hardware Installation Guide, Releases 2 Through 5.2
•Cisco ATM Services (AXSM) Configuration Guide and Command Reference for MGX Switches, Release 5.2
•Cisco MGX Route Processor Module (RPM-XF) Installation and Configuration Guide, Release 4
•Cisco MGX 8880 Media Gateway: A Guide to User Documentation.
•Release Notes for Cisco MGX 8850 (PXM1E/PXM45), Cisco MGX 8950, and Cisco MGX 8830 Switches, Release 5.2.00
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Cisco Product Security Overview
Cisco provides a free online Security Vulnerability Policy portal at this URL:
From this site, you can perform these tasks:
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Reporting Security Problems in Cisco Products
Cisco is committed to delivering secure products. We test our products internally before we release them, and we strive to correct all vulnerabilities quickly. If you think that you might have identified a vulnerability in a Cisco product, contact PSIRT:
•Emergencies — firstname.lastname@example.org
•Nonemergencies — email@example.com
Tip We encourage you to use Pretty Good Privacy (PGP) or a compatible product to encrypt any sensitive information that you send to Cisco. PSIRT can work from encrypted information that is compatible with PGP versions 2.x through 8.x.
Never use a revoked or an expired encryption key. The correct public key to use in your correspondence with PSIRT is the one that has the most recent creation date in this public key server list:
In an emergency, you can also reach PSIRT by telephone:
•1 877 228-7302
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Obtaining Technical Assistance
For all customers, partners, resellers, and distributors who hold valid Cisco service contracts, Cisco Technical Support provides 24-hour-a-day, award-winning technical assistance. The Cisco Technical Support Website on Cisco.com features extensive online support resources. In addition, Cisco Technical Assistance Center (TAC) engineers provide telephone support. If you do not hold a valid Cisco service contract, contact your reseller.
Cisco Technical Support Website
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Note Use the Cisco Product Identification (CPI) tool to locate your product serial number before submitting a web or phone request for service. You can access the CPI tool from the Cisco Technical Support Website by clicking the Tools & Resources link under Documentation & Tools. Choose Cisco Product Identification Tool from the Alphabetical Index drop-down list, or click the Cisco Product Identification Tool link under Alerts & RMAs. The CPI tool offers three search options: by product ID or model name; by tree view; or for certain products, by copying and pasting show command output. Search results show an illustration of your product with the serial number label location highlighted. Locate the serial number label on your product and record the information before placing a service call.
Submitting a Service Request
Using the online TAC Service Request Tool is the fastest way to open S3 and S4 service requests. (S3 and S4 service requests are those in which your network is minimally impaired or for which you require product information.) After you describe your situation, the TAC Service Request Tool provides recommended solutions. If your issue is not resolved using the recommended resources, your service request is assigned to a Cisco TAC engineer. The TAC Service Request Tool is located at this URL:
For S1 or S2 service requests or if you do not have Internet access, contact the Cisco TAC by telephone. (S1 or S2 service requests are those in which your production network is down or severely degraded.) Cisco TAC engineers are assigned immediately to S1 and S2 service requests to help keep your business operations running smoothly.
To open a service request by telephone, use one of the following numbers:
Asia-Pacific: +61 2 8446 7411 (Australia: 1 800 805 227)
EMEA: +32 2 704 55 55
USA: 1 800 553-2447
For a complete list of Cisco TAC contacts, go to this URL:
Definitions of Service Request Severity
To ensure that all service requests are reported in a standard format, Cisco has established severity definitions.
Severity 1 (S1)—Your network is "down," or there is a critical impact to your business operations. You and Cisco will commit all necessary resources around the clock to resolve the situation.
Severity 2 (S2)—Operation of an existing network is severely degraded, or significant aspects of your business operation are negatively affected by inadequate performance of Cisco products. You and Cisco will commit full-time resources during normal business hours to resolve the situation.
Severity 3 (S3)—Operational performance of your network is impaired, but most business operations remain functional. You and Cisco will commit resources during normal business hours to restore service to satisfactory levels.
Severity 4 (S4)—You require information or assistance with Cisco product capabilities, installation, or configuration. There is little or no effect on your business operations.
Obtaining Additional Publications and Information
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•Cisco Marketplace provides a variety of Cisco books, reference guides, and logo merchandise. Visit Cisco Marketplace, the company store, at this URL:
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•Packet magazine is the Cisco Systems technical user magazine for maximizing Internet and networking investments. Each quarter, Packet delivers coverage of the latest industry trends, technology breakthroughs, and Cisco products and solutions, as well as network deployment and troubleshooting tips, configuration examples, customer case studies, certification and training information, and links to scores of in-depth online resources. You can access Packet magazine at this URL:
•iQ Magazine is the quarterly publication from Cisco Systems designed to help growing companies learn how they can use technology to increase revenue, streamline their business, and expand services. The publication identifies the challenges facing these companies and the technologies to help solve them, using real-world case studies and business strategies to help readers make sound technology investment decisions. You can access iQ Magazine at this URL:
•Internet Protocol Journal is a quarterly journal published by Cisco Systems for engineering professionals involved in designing, developing, and operating public and private internets and intranets. You can access the Internet Protocol Journal at this URL:
•World-class networking training is available from Cisco. You can view current offerings at this URL:
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