Technical Documentation

Example: Configuring VoIP on an EX Series Switch Without Including LLDP-MED Support

You can configure voice over IP (VoIP) on an EX Series switch to support IP telephones. The Link Layer Discovery Protocol–Media Endpoint Discovery (LLDP-MED) protocol is sometimes used with IP phones to forward VoIP parameters from the switch to the phone. Not all IP phones support LLDP-MED, however.

This example describes how to configure VoIP on an EX Series switch without LLDP-MED and without 802.1X:

Requirements

This example uses the following hardware and software components:

  • JUNOS Release 9.1 or later for EX Series switches.
  • One EX4200 switch acting as an authenticator port access entity (PAE). The interfaces on the authenticator PAE form a control gate that blocks all traffic to and from supplicants until they are authenticated.
  • A IP phone that does not support LLDP-MED.

Before you configure VoIP, be sure you have:

Overview

Instead of using a regular telephone, you connect an IP telephone directly to the switch. An IP phone has all the hardware and software needed to handle VoIP. You also can power an IP telephone by connecting it to one of the Power over Ethernet (PoE) interfaces on the switch.

To configure VoIP on an EX Series switch to support an IP phone that does not support LLDP-MED, add the port to which you want to connect the IP phone as a member of the voice VLAN and configure the data VLAN as the native VLAN on the EX Series switch. This configuration ensures that the voice traffic and data traffic do not affect each other.

In this example, the interface ge-0/0/2 on the EX4200 switch is connected to a non-LLDP-MED IP phone.

Note: The implementation of a voice VLAN on an IP telephone is vendor-specific. Consult the documentation that came with your IP telephone for instructions on configuring a voice VLAN. For example, on an Avaya phone, you can ensure that the phone gets the correct VoIP VLAN ID even in the absence of LLDP-MED by enabling DHCP option 176.

Configuration

To configure VoIP without LLDP-MED or 802.1X authentication:

CLI Quick Configuration

To quickly configure VoIP, copy the following commands and paste them into the switch terminal window:


[edit]


set vlans data-vlan vlan-id 77


set vlans voice-vlan vlan-id 99


set vlans data-vlan interface ge-0/0/2.0


set ethernet-switching-options voip interface ge-0/0/2.0 vlan voice-vlan


set ethernet-switching-options voip interface ge-0/0/2.0 forwarding-class assured-forwarding


set interfaces ge-0/0/2 unit 0 family ethernet-switching vlan members voice-vlan


set interfaces ge-0/0/2 unit 0 family ethernet-switching native-vlan-id data-vlan

Step-by-Step Procedure

Configure VoIP:

  1. Configure the VLANs for data and voice:

    [edit vlans]
    user@switch# set data-vlan vlan-id 77
    user@switch# set voice-vlan vlan-id 99
  2. Configure the VLAN data-vlan on the interface:

    [edit vlans]
    user@switch# set data-vlan interface ge-0/0/2.0
  3. Configure VoIP on the interface and specify the assured-forwarding forwarding class to provide the most dependable class of service:

    [edit ethernet-switching-options]
    user@switch# set voip interface ge-0/0/2.0 vlan voice-vlan
    user@switch# set voip interface ge-0/0/2.0 forwarding-class assured-forwarding
  4. Add the interface as a member of the voice VLAN:

    [edit interfaces]
    set ge-0/0/2 unit 0 family ethernet-switching vlan members voice-vlan
  5. Configure data-vlan as native to this trunk interface:

    [edit interfaces]
    user@switch# set ge-0/0/2 unit 0 family ethernet-switching native-vlan-id data-vlan

Results

Display the results of the configuration:

[edit]
user@switch# show configuration
interfaces {
ge-0/0/2 {
unit 0 {
family ethernet-switching {
port-mode trunk;
vlan {
members voice-vlan;
}
native-vlan-id data-vlan;
}
}
}
}
vlans {
data-vlan {
vlan-id 77;
interface {
ge-0/0/2.0;
}
}
voice-vlan {
vlan-id 99;
}
}
ethernet-switching options {
voip {
interface ge-0/0/2.0 {
vlan voice-vlan;
forwarding-class assured-forwarding;
}
}
}

Verification

To confirm that the configuration is working properly, perform the following task:

Verifying the VLAN Association With the Interface

Purpose

Display the interface state and VLAN membership.

Action


 Ethernet-switching table: 0 entries, 0 learned

user@switch> show ethernet-switching interfaces 
Interface   State    VLAN members           Blocking 
ge-0/0/0.0  down     default                unblocked
ge-0/0/1.0  down     employee-vlan          unblocked
ge-0/0/5.0  down     employee-vlan          unblocked
ge-0/0/3.0  down     employee-vlan          unblocked
ge-0/0/8.0  down     employee-vlan          unblocked
ge-0/0/10.0 down     default                unblocked
ge-0/0/11.0 down     employee-vlan          unblocked
ge-0/0/23.0 down     default                unblocked
ge-0/0/2.0  up       voice-vlan             unblocked
                     data-vlan              unblocked

Meaning

The field VLAN members shows that the ge-0/0/2.0 interface supports both the data-vlan VLAN and voice-vlan VLAN. The State field shows that the interface is up.

Published: 2009-08-05