VOIP CONFIG

[ghasemashjaei]

HELLO Guys

I need your point of view about how can I run the this scenario

My IP Phone (Brand name: Polycom) should get IP from our Internet Service Provider DHCP server. 

In order to do that the RJ45 cable from ISP switch (Cisco ASR 1000 x) connected to my 3750-G switch via interface Gigaethernet 24.

Our telephone connect to our HP Procure 2910al48G-Poe switch via port number 2.

My configuration on 3750 SW

SW-B6-C3750(config)vlan 2
SW-B6-C3750(config-vlan)name " VOICE-VLAN"

SW-B6-C3750 (config)interface vlan 2
SW-B6-C3750 (config-if)ip address 172.16.5.253 255.255.255.0
SW-B6-C3750 (config-if)do wr

SW-B6-C3750(config)interface gigabitEthernet 1/0/24
SW-B6-C3750(config-if)description  BOUYGUES-VOICE-VLAN2
SW-B6-C3750(config-if)switchport access vlan 2
SW-B6-C3750(config-if)switchport trunk encapsulation dot1q
SW-B6-C3750(config-if)switchport voice vlan dot1p
SW-B6-C3750(config-if)switchport mode trunk

Show run

interface GigabitEthernet1/0/24

description BOUYGUES--VOICE--VLAN2

 switchport access vlan 2

 switchport trunk encapsulation dot1q

 switch-port trunk allowed vlan 2

 switch-port mode trunk

 switch port voice vlan 2

 no ip address

 mls qos trust cos

 no mdix auto

 spanning-tree portfast trunk

interface Vlan2

description VOICE-VLAN

ip address 172.??.??.??  255.255.255.0

Thank you in advance

Best

Ghasem

[Giuseppe Larosa]

Hello Ghasem,

under Cisco 3750 SVI interface vlan 2 you need

int vlan 2

ip helper-address <DHCP-server-IP-address>

Access ports to which the IP phones connect should use the switchport voice vlan 2

Note:

The DHCP server needs to have configured the scope for the phones with the DHCP option used by Polycom to access the VOIP server.

Also the use of LLDP MED instead of CDP if supported by C3750 should be considered.

Hope to help

Giuseppe

[ghasemashjaei]

Dear Giuseppe

First of all thanks for your comment, I did that command ( ip helper-address ) But still my phone did not get IP from ISP. phones should not get IP from our local DHCP server,

Thank you 

Ghasem

[Giuseppe Larosa]

Hello Ghasem,

have you configured the ip helper-address with the IP address of the ISP's DHCP server ?

If so you need to contact the ISP tech people that manages the server to verify that they receive the DHCP relayed requests from your C3750. And also they should verify the scope settings.

What models of Polycom phones are used ?

Hope to help

Giuseppe

[ghasemashjaei]

Hello, 

Yes, I've already configured.

Polycom vvx 411 

Thank you 

Best 

Ghasem

[Giuseppe Larosa]

Hello Ghasem,

the following methods are supported by the phones for voice vlan discovery

VLAN-CDP, DHCP VLAN discovery, LLDP-MED for VLAN discovery

see

https://www.polycom.com/content/dam/polycom/common/documents/data-sheets/vvx-400-series-data-sheet-enus.pdf

Verify what are the settings on the phones.

user guide link

https://support.polycom.com/content/dam/polycom-support/products/voice/business-media-phones/downloads/previous-versions/archived-documents/en/3725-46211-007a-vvx-userguide-5-6-0.pdf

Edit:

see also the following document about Vlan discovery on polycom phones

https://knowledgebase-iframe.polycom.com/kb/viewdocument.do?noCount=true&externalId=36957&sliceId=1&cmd=&ViewedDocsListHelper=com.kanisa.apps.common.BaseViewedDocsListHelperImpl

Hope to help

Giuseppe

[ghasemashjaei]

Hello Giuseppe

Tnx for your replying, Still did not get IP from our ISP. :( 

Best

Ghasem