Will all Cisco Phones work with a Sip Trunk?

Unanswered Question
May 21st, 2009
User Badges:

Our company is looking in to using a Sip trunk instead of the analog lines that we are currently using for our outside the office calls. We currently have 7975 and 7921 phones and we use a UC520. Will we lose any of the functionality of the phones that we currently use, such as Live Record, Conferencing, etc if we go with a SIP Trunk? Do we need to stay away from any Cisco phones for this reason?

  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 0 (0 ratings)
Steven DiStefano Thu, 05/21/2009 - 05:19
User Badges:
  • Blue, 1500 points or more

The UC500 is actually "better" with SIP Trunks (Converged network, ROI, Efficiencies of DIDs, etc etc).

You can still operate the Cisco IP phones in SCCP (Skinny) mode, and the IP-PBX (UC500) Registers 'SIP' to the SP of your choice.

The following SIP Trunk Providers achieved "designated" status and are built into our CCA (configuration assistant)

AT&T, Broadview, BT, Cbeyond, NUVOX, Paetec, XO COmmunications, and coming very soon COVAD and One COmmunications.

Others can work as well, just havent run the suite of tests for us is all.

You will loose no functionality that I know of....in fact, you gain alot.....

Steve DiStefano

SE, US Field Channels

lbroering Thu, 05/21/2009 - 08:25
User Badges:

Thanks for information and the quick response.

John Platts Thu, 05/21/2009 - 08:32
User Badges:
  • Silver, 250 points or more

Yes, SIP Trunks will work with all of the Cisco phones. You can use the phones that you have with SIP trunking.

Switching to SIP trunking involves porting phone numbers, and reconfiguring the UC520 unit. You might have to use CLI to configure SIP trunking. Two reasons that you might have to use CLI are:

  • Some SIP providers require settings that cannot be set through CCA
  • CCA might mess up your configuration

You will not lose functionality when you switch to SIP trunking. You will actually gain the following functionality by switching to SIP trunking if you did not have these features with your original PSTN connectivity (such as analog lines or PRI T1):

  • Caller ID
  • Ability to use the CME TAPI provider and Cisco Unified CallConnector
  • Ability to forward calls to an off-site number
  • Ability to transfer calls to an off-site number
  • Ability to conference people into the call
Marcos Hernandez Sun, 05/24/2009 - 10:12
User Badges:
  • Blue, 1500 points or more

One important clarification:

In Cisco jargon "SIP Trunk" refers to the support of SIP providers for VoIP calls across the WAN. The UC500 behaves as a User Agent in this case. What you are talking about John is SIP CME, where the UC500 is the proxy/registrar for IP phones running a SIP load.




This Discussion

Related Content