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Connecting EX-series Ethernet switches with VoIP phones



Article ID: KB11308 KB Last Updated: 10 Aug 2020Version: 4.0

EX-series switches support Voice over IP (VoIP).  EX-series switches accommodate implementation scenarios that include an IP phone and a user’s PC connected to a single switch port.  The Voice VLAN feature is used on the EX series switches for this purpose.  The Voice VLAN enables a single access port to accept untagged data traffic as well as tagged voice traffic and associate each type of traffic with distinct and separate VLANs. Voice traffic can now be treated differently, generally with higher priority than common data traffic. VoIP also uses LLDP (Link Layer Discovery Protocol) and LLDP-MED ( Link Layer Discovery Protocol Media Endpoint Discovery) protocol information to forward VoIP parameters from the RADIUS server to the phone, for example VLAN and COS settings.


Below is a configuration example for connecting a VoIP phone and a PC to the EX series Ethernet switches.

Known Considerations:

  1. The phone is being connected to interface ge-0/0/10
  2. The user's PC is connected to the IP phone
  3. Phone is capable of LLDP-MED
  4. The untagged data VLAN used in this example is vlan_data
  5. The tagged voice VLAN used in this example is vlan_voice

Configuring Voice VLAN functionality:
  1. The interface ge-0/0/10 is configured to be in the data vlan for the user's PC.
    user@switch# set interface ge-0/0/10 unit 0 family ethernet-switching vlan members vlan_data
  2. Configure the voice VLAN on the interface ge-0/0/10 for the user's IP phone
    user@switch# set ethernet—switching—options voip interface ge-0/0/10 vlan vlan_voice
  3. Specify the forwarding class assured-forwarding for the most dependable service
    user@switch# set ethernet—switching—options voip interface ge-0/0/10 forwarding-class assured-forwarding
  4. Configure the voice VLAN and data VLAN for the EX series switch
    user@switch# set vlans vlan_data vlan-id 100
    user@switch# set vlans vlan_voice vlan-id 200


Issue the 'show vlans' operational mode command to confirm port ge-0/0/10 has been assigned to vlan_data and vlan_voice
user@switch> show vlans
Name            Tag        Interfaces
vlan_data       100        ge-0/0/10*, ge-0/0/12, ge-0/0/13
vlan_voice      200        ge-0/0/10*, ge-0/0/15, ge-0/0/17

Configuring Basic LLDP-MED functionality:

If the phone is not capable of LLDP-MED, the following configuration step is NOT required. If the phone does not support LLDP-MED, the voice  VLAN  ID will be required to be manually set on the IP phone.
  1. Configure LLDP-MED on the interface connected to the IP Phone
    user@switch# set protocols lldp-med interface ge-0/0/10.0
  2. Configure the frequency at which LLDP-MED advertisements are sent from the switch in the first second after it has detected an LLDP-MED device:
    user@switch# set protocols lldp-med fast-start 6
  3. Commit the configuration
    user@switch# commit


Display the configuration settings using sh lldp operational mode command
user@switch> show lldp

LLDP                   : Enabled
Advertisement interval : 30 seconds
Transmit delay         : 2 seconds
Hold timer             : 2 seconds
Config Trap Interval   : 60 seconds
Connection Hold timer  : 300 seconds
LLDP MED               : Enabled
MED fast start count   : 6 Packets
Interface       LLDP       LLDP-MED
all            Enabled        -        
ge-0/0/10.0      -          Enabled

  • If the IP phone is capable of doing Power over Ethernet (POE) this can be configured on the EX-series Ethernet switch.  When configuring and connecting a POE capable IP phone or device to the EX-series Ethernet switch bear in mind the type of EX-series switch available to you.  EX-series Ethernet switches are available with options of full (all ports) or partial (8 ports) Power over Ethernet (PoE) capability.  In the partial (8 ports) POE model, the first 8 ports, ports 0 through 7 are available for POE.

  • If the phone uses an external power adapter the following configuration step is NOT required.

    Configure POE for a particular interface
user@switch# set poe interface ge-0/0/10
Modification History:
2020-08-10: Minor, non-technical edits.
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