Solved: SG300 voice vlan problem with UC520

yong khang NG · ‎03-13-2011

Hi Forumers'

My problem statement:

- refere to attached topology.png, this is how my network structure look like

- the IP phone after boot cannot get connected, so it can't download the XML config file from UC520. suspicious switching problem.

- my configuration shown at topology.png and my vlan voice config show as voice vlan setting.png

- My requirement is SG300 switch single switchport to carry vlan data and vlan voice.

- what is the trunking mode for voice VLAN siwth a IP phone+data should i configure? is it switchport voice vlan vvid, switchport voice vlan dot1p, switchport voice vlan untagged or switchport voice vlan none to suite above requirement?

thanks

Noel

nimusell · ‎03-24-2011

Hello Noel,

Sorry for the late reply, things have been quite hectic around here lately

1. Why use trunk? the UC520 only have vlan voice (vlan 20)

Do you mean that the data VLAN is handled by another device ? Still I would leave it as a trunk in order to be able manage the UC through the data VLAN. (Unless for security or other reasons you would choose otherwise of course)

2. The UC520 got CUE (voice messaging), how should i design the service module uplink to the core switch?

Nothing in particular has to be done for this, CUE is handled and routed inside the UC520, the CUE vlan (default ID =90) is only used if you have another CUE in the network

1. i guess i did this: swithcport tagged vlan 20, untagged vlan 10. is it ok for this setting?

If the Voice Vlan on the switch and on the UC520 has been defined as VLAN 20 (default = VLAN 100) this is perfect. Verify if both on the UC and on the switch, the voice VLAN ID is set to 20.

1. so if i just point the phone to vlan 20 (vlan voice), should i create the LLDP network policy?

If you are ready to configure the VLAN manually on the phone, you don't need the LLDP policy, that is correct.

The LLDP policy is being used for having the phones automatically choose the VLAN you defined, so you don't need to set it manually.

Hope this answers your questions ?

Best regards,

Nico Muselle

Sr. Network Engineer - CCNA

View solution in original post

nimusell · ‎03-13-2011

Hi Noel,

Thank you for participating in the Cisco Small Business Support Forum. My name is Nico Muselle from Cisco Sofia S-TAC.

I've taken a look at your topology and Voice Vlan configuration and it seems fine to me, the things to keep in mind to make this work are the following :

- make sure the port connecting to the UC is configured as a trunk allowing both VLANs (both on the switch and on the UC520)
- make sure the ports connecting both a phone and a computer are configured as trunk ports with PVID set to the default vlan and then either staically assigned to the voice vlan or have auto voice vlan enabled
as the SG300 switch does not support CDP (for now), you need to either configure the VLAN on the phone itself, either create an LLDP network policy to have the phone automatically assigned to the Voice VLAN. Of course you need to attach this network policy to the ports connecting phones and to the trunk going to your UC.
then reset your phone to factory defaults and everything should work just fine

Hope this helped, if you need any help with the config, don't hesitate to help

Best regards,

Nico Muselle

Sr. Network Engineer - CCNA

yong khang NG · ‎03-16-2011

hi nico,

thanks for the reply. few thing still need your clarification:

my question will be in blue font

•- make sure the port connecting to the UC is configured as a trunk allowing both VLANs (both on the switch and on the UC520)
1. Why use trunk? the UC520 only have vlan voice (vlan 20)
2. The UC520 got CUE (voice messaging), how should i design the service module uplink to the core switch?

•- make sure the ports connecting both a phone and a computer are configured as trunk ports with PVID set to the default vlan and then either staically assigned to the voice vlan or have auto voice vlan enabled
1. i guess i did this: swithcport tagged vlan 20, untagged vlan 10. is it ok for this setting?

•as the SG300 switch does not support CDP (for now), you need to either configure the VLAN on the phone itself, either create an LLDP network policy to have the phone automatically assigned to the Voice VLAN. Of course you need to attach this network policy to the ports connecting phones and to the trunk going to your UC.
•then reset your phone to factory defaults and everything should work just fine
1. so if i just point the phone to vlan 20 (vlan voice), should i create the LLDP network policy?

thank you

Noel

nimusell · ‎03-24-2011