The documentation set for this product strives to use bias-free language. For the purposes of this documentation set, bias-free is defined as language that does not imply discrimination based on age, disability, gender, racial identity, ethnic identity, sexual orientation, socioeconomic status, and intersectionality. Exceptions may be present in the documentation due to language that is hardcoded in the user interfaces of the product software, language used based on RFP documentation, or language that is used by a referenced third-party product. Learn more about how Cisco is using Inclusive Language.
This chapter describes how to configure Voice VLAN on the Cisco 2520 Connected Grid Switch
(CGS 2520) and the Cisco Connected Grid 10-port Ethernet Switch Module Interface (ESM).
Voice VLAN is referred to as an auxiliary VLAN in some Catalyst 6500 family switch documentation.
Note For complete syntax and usage information for the commands used in this chapter, see the command reference for 15.0(2)SE listed in Supported Hardware.
|
|
|
---|---|---|
Cisco 2500 Series Connected Grid Switches Configuration Guides |
||
CGS 2520 Switch Software Configuration Guide, 12.2(53)EX (Configuring VLANS) |
||
Catalyst 3750 Switch Command Reference, Cisco IOS Release 15.0(2)SE and Later |
||
Connected Grid Ethernet Switch Module Interface Card Getting Started Guide |
The Voice VLAN feature enables access ports to carry IP voice traffic from an IP phone.
When using a configurable IP phone, you can configure it to forward traffic with an IEEE 802.1p priority. You can also configure the switch to trust or override the traffic priority assigned by an IP phone. For example, a Cisco IP phone (such as 7960 series) contains an integrated three-port 10/100 switch as shown in Figure 6-1. The ports provide dedicated connections to these devices:
Figure 6-1 shows one way to connect a Cisco IP Phone.
Figure 6-1 Cisco 7960 IP Phone Connected to a Switch
You can configure an access port with an attached Cisco IP Phone to use one VLAN for voice traffic and another VLAN for data traffic from a device attached to the phone. You can configure access ports on the switch to send Cisco Discovery Protocol (CDP) packets.
The switch can also process tagged data traffic (traffic in IEEE 802.1Q or IEEE 802.1p frame types) from the device attached to the access port on the Cisco IP Phone (see Figure 6-1). You can configure Layer 2 access ports on the switch to send CDP packets that instruct the attached phone to configure the phone access in trusted mode. In this case, all traffic received through the access port on the Cisco IP Phone passes through the phone unchanged.
Note Untagged traffic from the device attached to the Cisco IP Phone passes through the phone unchanged, regardless of the trust state of the access port on the phone.
These sections contain this configuration information:
The Voice VLAN feature is disabled by default.
When the Voice VLAN feature is enabled, all untagged traffic is sent according to the default CoS priority of the port.
These are the Voice VLAN configuration guidelines:
Note Trunk ports can carry any number of Voice VLANs, similar to regular VLANs. The configuration of Voice VLANs is not required on trunk ports.
Voice VLAN should be present and active on the switch for the IP phone to correctly communicate on the Voice VLAN. Use the show vlan privileged EXEC command to display the configured VLANs.
– They both use IEEE 802.1p or untagged frames.
– The Cisco IP Phone uses IEEE 802.1p frames, and the device uses untagged frames.
– The Cisco IP Phone uses untagged frames, and the device uses IEEE 802.1p frames.
– The Cisco IP Phone uses IEEE 802.1Q frames, and the Voice VLAN is the same as the access VLAN.
– Dynamic access port. (See the Configuring Dynamic-Access Ports on VMPS Clients section within the Configuring VLANs chapter of CGS 2520 Switch Software Configuration Guide, 12.2(53)EX.)
– IEEE 802.1x authenticated port. (See the Configuring 802.1x Readiness Check section within the Configuring IEEE 802.1x Port-Based Authentication chapter of the CGS 2520 Switch Software Configuration Guide, 12.2(53)EX.)
Note If you enable IEEE 802.1x on an access port on which a Voice VLAN is configured and to which a Cisco IP Phone is connected, the phone loses connectivity to the switch for up to 30 seconds.
– Protected port. (See the Configuring Protected Ports section within the Configuring Port-Based Traffic Control chapter of the CGS 2520 Switch Software Configuration Guide, 12.2(53)EX.)
– A source or destination port for a SPAN or RSPAN session.
– Secure port. (See the Configuring Port Security section within the Configuring Port-Based Traffic Control chapter of the CGS 2520 Switch Software Configuration Guide, 12.2(53)EX.)
Note When you enable port security on an interface that is also configured with a Voice VLAN, you must set the maximum allowed secure addresses on the port to two plus the maximum number of secure addresses allowed on the access VLAN. When the port is connected to a Cisco IP Phone, the phone requires up to two MAC addresses. The phone address is learned on the Voice VLAN and might also be learned on the access VLAN. Connecting a PC to the phone requires additional MAC addresses.
Because a Cisco IP Phone also supports a connection to a PC or other device, a port connecting the switch to a Cisco IP Phone can carry mixed traffic. You can configure a port to decide how the Cisco IP Phone carries voice traffic and data traffic.
You can configure a port connected to the Cisco IP Phone to send CDP packets to the phone to configure the way in which the phone sends voice traffic. The phone can carry voice traffic in IEEE 802.1Q frames for a specified Voice VLAN with a Layer 2 CoS value. It can use IEEE 802.1p priority tagging to give voice traffic a higher priority and forward all voice traffic through the native (access) VLAN. The Cisco IP Phone can also send untagged voice traffic or use its own configuration to send voice traffic in the access VLAN. In all configurations, the voice traffic carries a Layer 3 IP precedence value (the default is 5).
Beginning in privileged EXEC mode, follow these steps to configure voice traffic on a port:
This example shows how to configure a port connected to a Cisco IP Phone and how to use IEEE 802.1p priority tagging for voice traffic, and to use the default native VLAN (VLAN 0) to carry all traffic:
To return the port to its default setting, use the no switchport voice vlan interface configuration command.
Note To set priority of incoming data frames, the switch must be running the LAN Base image.
You can connect a PC or other data device to a Cisco IP Phone port. To process tagged data traffic (in IEEE 802.1Q or IEEE 802.1p frames), you can configure the switch to send CDP packets to instruct the phone how to send data packets from the device attached to the access port on the Cisco IP Phone. You can configure the phone to not change (trust) or to override (not trust) the priority of frames arriving on the phone port from connected devices.
Beginning in privileged EXEC mode, follow these steps to set the priority of data traffic received from the non-voice port on the Cisco IP Phone:
This example shows how to configure a port connected to a Cisco IP Phone to not change the priority of frames received from the PC or the attached device:
To return the port to its default setting, use the no switchport priority extend interface configuration command.
|
|
---|---|