Voice VLAN / SIP Registration problem

[dotrainexpress]

Hello!

I have a Netvanta 4430 running DHCP for a Data vlan (10) and Voice vvlan (100). I have NEC phones that will register to the SIP server (on the data vlan) if the port the phone is plugged into is hard coded to use the data vlan. However, when configuring the port to use data or voice, the phone will correctly get the voice vlan IP, but will not register to the SIP server.

I've connected my laptop after hard-coding the port to voice vlan and am able to ping the gateway and SIP server without problem.

Here is my DHCP setup:

ip dhcp-server pool "DATA_DHCP"

  network 10.66.5.0 255.255.255.0

  domain-name "company.net"

  dns-server 10.13.29.10 10.13.29.9

  netbios-name-server 10.13.29.10 10.13.29.9

  default-router 10.66.5.1

  lease 7

  option 128 ascii VLANID=10

!

ip dhcp-server pool "Voice_DHCP"

  network 172.16.5.0 255.255.255.0

  dns-server 10.13.29.10 10.13.29.9

  default-router 172.16.5.1

  lease 30

  option 120 hex 0A420515

  option 15 ascii company.local

  option 128 ascii VLANID=100

  option 66 ascii 10.66.5.21

  option 2 ascii 4294945696

Any ideas or thoughts?

[Anonymous]

:

Thank you for asking this question in the support community.  When you get a chance will you please reply with a copy of the configuration (remember to remove any information that may be sensitive to the organization)?  Also, is there any additional information you can provide for the rest of the network?  Based on what you've indicated, the phones are plugged into a switch.  Are the ports on the switch configured as VLAN access ports or trunk ports?  What VLAN do the phones boot up in?  You said when the phones are on the data VLAN, they register successfully, but when they are in the voice VLAN, they fail registration.  When the phones fail registration, what error does the SIP server provide?

Please, reply to this post with any additional information and questions.  I will be happy to help in any way I can.

Levi

[Anonymous]

Hey dotrainexpress, what is the SIP Server expecting for SIP Server ports... NEC IP phone's default 5060 but this could be different in the SIP Server.

I am also having issues getting a DT7xx NEC IP Phone to get the SIP Server IP and SIP Server Ports from a DHCP Server on a Netvanta 4305 that I have in my lab. I am using the default VLAN on a Netvanta 1238 to connect phones to, and I have the 1238 connected to eth 0/2 on the 4305. I get valid IP/Default Gateway/DNS for the phone, but 1st SIP Server shows "Invalid IP Address" and the 1st SIP Server port shows the default port (5060) not 5080.

Below is a snippet from my 4305's DHCP's config and the ethernet ports. (very basic config... just trying to get DHCP to push those settings so I want to take out as many variables as possible. Let me know if you would like to see more of the config)

SIP Server IP = 192.168.20.47

SIP Server Port = 5080

!

ip dhcp-server pool "2"

  network 192.168.20.0 255.255.255.0

  dns-server 8.8.8.8

  default-router 192.168.20.254

  option 168 hex 0x13D8

  option 120 hex 0xC0A8142F

!

!

!

interface eth 0/2

  ip address  192.168.20.254  255.255.255.0

  no shutdown

!

!

!

Thanks

[dotrainexpress · Accepted solution]

Hi -

Actually, the problem ended up being that I couldn't connect to (or ping) the dns server from the voice vlan.

My fix:

Since the only things that were getting a dhcp address from the voice vlan would be phones, I setup the phone system server as a dns server and pointed the voice scope to that. Rebooted the phones and they came up working.

Thanks!

[Anonymous]

:

I went ahead and flagged this post as “Assumed Answered.”  If any of the responses on this thread assisted you, please mark them as either Correct or Helpful answers with the applicable buttons.  This will make them visible and help other members of the community find solutions more easily.  If you still need assistance, I would be more than happy to continue working with you on this - just let me know in a reply.

Levi

[Anonymous]

I figured out why I was getting a bad SIP Server Address.

When using option 120 you have to put a 1 in hex to indicate that the IP address is a IPv4 address. So the corrected version of the DHCP Server Pool looks like this:

!

ip dhcp-server pool "2"

  network 192.168.20.0 255.255.255.0

  dns-server 8.8.8.8

  default-router 192.168.20.254

  option 120 hex 01C0A8142F

!

You can find out more info on dhcp option 120 by refering to RFC3361  http://www.rfc-editor.org/rfc/rfc3361.txt

I was not able to get option 168 to work, but in order to get it to work on a Window Server you have to create a custom vendor class...etc.

I hope this helps out some folks.

[Anonymous]

I went ahead and flagged the "Correct Answer" on this post to make it more visible and help other members of the community find solutions more easily. If you don't feel like the answer I marked was correct, feel free to come back to this post and unmark it and select another in its place with the applicable buttons.  If you still need assistance, we would be more than happy to continue working with you on this - just let us know in a reply.

Thanks,

Noor