Voice vlan for non-Cisco phones?

[rpastor]

Hello friends,

Simple, basic question.  Do voice vlans work for non-Cisco phones, specifically Shoretels?  When reading about VV's, I see that CDP is required.  Hence, the question --

Thanks much,

Richard P.

[John Blakley]

CDP is only required for Cisco phones when using "switchport voice vlan ". You can create a normal vlan and trunk the port to the phone/workstation. You'll put your phone on your "voice" vlan and your workstation on the normal data vlan. I run Avaya phones all over the place like this with no issues.

HTH,

John

[Peter Paluch]

Hello John,

Yes, that is a workable configuration but I suspect it would work even with switchport mode access and switchport voice vlan. The only issue is that the Shoretels would be unable to learn about the voice VLAN automatically via CDP, and would have to be configured with the voice VLAN ID manually. Apart from that, this configuration should work just fine, and to be completely honest, I like it better than trunking - it is more clean. On a trunk, to be protected, you'd need to configure the allowed VLAN list to allow only for the access VLAN and voice VLANs to be carried on it.

Best regards,

Peter

[rpastor]

OK, I was afraid of that.  So that means my config is wrong.

On the L2 switch:

interface FastEthernet0/16

switchport access vlan 9

switchport mode access

switchport voice vlan 88

Both vlans are trunked through to the L3 upstream, where the SVI is configured.  It is the default route.  DHCP is configured with scopes in both vlans. The DHCP server can be reached.  But the phone keeps getting an address in VL9.  ... I wonder if there is something I need to configure in the phones?  Right now, there is a DHCP Option 156 which specifies the ftp server address, country and language codes, and "layer2tagging=0".  Just for the hell of it, I changed that last option to "1", even though the DHCP server is apparently not being reached.  Didn't help.  I'm stumped.

[John Blakley]

Richard,

Usually, the phone will have a special string that only it knows. Option 242 for Avaya allows me to set the call server, vlan information, and http configuration server, etc. You may have the same type options with Shoretel. (I've never seen a Shoretel system, so don't quote me.) The option string goes in your data vlan (vlan 9). The workstations will ignore the string, but the phones will pick it up and flip over to the voice vlan that you have configured in the string. If that doesn't work, I would suggest manually configuring a phone to see if it will work at all in this configuration and put it on the voice vlan that you have configured.

Peter,

I've honestly never tried an Avaya phone on the "switchport voice vlan", but you're right. I do specify the vlans to allow on the trunk to every port that has a phone, but otherwise I don't have any experience with non-Cisco phones on the voice vlan.

HTH,

John

[rpastor]

Thank you both.  I'll try some things tomorrow and let you know.

Richard

[Andrew Cink · Accepted solution]

I happen to have at my former job been a ShoreTel guru.

Your configuration is valid, however, you need to use DHCP to make your ShoreTel phones aware of the voice vlan.

Your DHCP server needs to have the following string value

ftpservers=x.x.x.x,layer2tagging=1,vlanid=88

Your phones will need to be served this DHCP option 156 on both the data vlan (access vlan) and voice vlan.

When your phone boots, it will DHCP on the data vlan, when it learns the option 156, it will say, oh, I need to tag my voice packets vlan 88, it will set itself to tagging on vlan 88, reboot itself, and dhcp on vlan 88. Assuming it gets an IP address and option 156 on vlan 88, it will then proceed to FTP download firmware and boot as it should.

Make sure your ShoreTel server IP Phone address map has the voice vlan network in it, or when the phone requests service from the server, the server will not know what site to assign that device to, and thus will never assign the phone an IP phone resource and it will go into no service.

Good luck!

Andy, ex-ShoreTel guru and now Cisco IP Telephony neophyte

[ljoenens]

Maybe something useful;

We used following configuration in a C3750 for connecting Avaya IP phones on Cisco PoE ports;

Remember that connecting your IP phone on a separate LAN port, doubles your cabling & pathcing. I think the advantage is just to use a common UTP for both IP phone and laptop.

Don't forget neither that inside an IP phone, there's a small switch, so it makes sense to configure a trunk interface between the LAN switch port and the IP phones.

ip dhcp excluded-address x.x.x.x y.y.y.y
!
ip dhcp pool Data
   network x.x.x.x 255.255.255.0
   default-router x.x.x.1
   dns-server x.x.x.x y.y.y.y.y
   option 242 ascii L2Q=1,L2QVLAN=5
   option 176 ascii L2Q=1,L2QVLAN=5
!
ip dhcp pool VoIP
   network x.x.x.x 255.255.255.0
   default-router x.x.x.1
   option 242 ascii MCIPADD=x.x.x.x,x,x,x,x,MCPORT=1719,HTTPSRVR=x.x.x.x,TFTPSRVR=x.x.x.x,VLANTEST=0
   option 176 ascii MCIPADD=x.x.x.x,x,x,x,x,MCPORT=1719,HTTPSRVR=x.x.x.x,TFTPSRVR=x.x.x.x,VLANTEST=0

Note:

MCIPADD = IP addr. of Avaya's CLAN (Call Mgr) (make sure the last IP addr is the local one, the survivable processor)

HTTPSRVR = IP addr. of any windows server containing the phone's image; image will only be uploaded to the IP phone if the phone's version is older.

You can use a TFTP server instead of the HTTP server.

Good luck!

[rpastor]

Andrew Cink - right on the money.    Thank you, all.