What are the meaningful advantages/disadvantages of SIP vs. SCCP phones on CUCM 9+

[voip7372]

Before we buy lots of phones, can you tell me if there's any good reasons why we should use one protocol over the other?  (with CUCM 9 or higher)  Does it makes sense to just leave any new phones we buy working as SCCP?...or are there some really good reasons why havning (for example) a 8945 or 6945 phone be SIP?  We're building a new system and I think it makes sense to decide on SIP or SCCP for the phones right now. 

Thanks

[Chris Deren · Accepted solution]

It does not really matter as the feature parity between phones that support both protocols is nearly identical. CUCM is a protocol translator and handles mixed protocols very well. I still use SCCP on the phones that support it and SIP on SIP only phones.

Chris

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[voip7372]

Ok, thanks.  That's pretty much what I was wondering about...if there would be major features not available on phones runing SIP that are available on SCCP phones or vice versa.  I'd just assume leave them SCCP unless there was a good reason not to, now of in the forseeable future.

[markbatts]

Just to add if you're looking to go SIP provider at any stage in the future then they do recommend SIP end to end though its not a dependency.

[Rob Huffman]

Hi there,

I love the answer from my friend Chris here (+5 buddy!) You can't

go wrong with this advice

I just thought I would add that for any phones that can run both

SCCP & SIP you find these comparison guides which may help;

Feature Support by Protocol for the Cisco Unified IP Phone 8941 and 8945

http://www.cisco.com/en/US/docs/voice_ip_comm/cuipph/8941_8945/8_5/english/admin_guide/6921apxg.html

Cisco Unified IP Phone 6921, 6941, 6945, and 6961 Administration Guide  for Cisco Unified Communications Manager 9.0 (SCCP and SIP) - Feature Support by Protocol

http://www.cisco.com/en/US/docs/voice_ip_comm/cuipph/6921_6941_6945_6961/9_0/english/admin_guide/P690_BK_4AB91FB_00_admin-6921-6941-6945-6961_appendix_01111.html

Cheers!

Rob

"Why do the best things always disappear " 

- The Band

[Chris Deren]

This is the first time I hear of such recommendation. With call agent such as CUCM there is no direct signaling between The phone and SIP provider so this is irrelevant unless you have old 79x0 type phones that don't support RfC2833, EO, etc.

Chris

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[voip7372]

Ah....seems you answered my last question :-)

[voip7372]

Thanks everyone.  We do at some point plan on going with SIP trunks (replacing ISDN PRI trunks).  I imagine that might be a few years away.  Hmmm....that's something to think about.   So, I know if you convert between G.729 and G.711, you need a transcoder with DSPs for that, but how does it work when converting between SIP coming in from outside trunks to get to the SCCP phone?  I assu,e the CUCM server can handle that on its own, without the need for more external hardware of some sort? 

[john-guy]

I performed a search on whether there is an advantage of using SIP over SCCP for Cisco phones where the consensus is no difference.  I'm taking a different approach where URI dialing is becoming more common and Cisco video endpoints run SIP appear to make it less processor intensive converting between SCCP, H.323 and SIP using protocol translators such as CUCM or VCS.  With that said are there any advantages migrating all voice and video endpoints to SIP?  Since SIP is promoted for Video and URI dialing why would a system become deployed using SCCP other than losing phone features?

Thank you,

John

[Vivek Batra]

Although SIP is most popular and hot protocol outside Cisco whether for service providers or other PBX manufacturer but within Cisco atleast for terminals, SCCP is still more stable, reliable including as you mentioned more features than SIP. 

[Marcelo Morais]

Hi john-guy,

 this is an excellent discussion ... to a better understanding of this topic we should take a look in the SCCP & SIP moment.

 In the past, SCCP had the advantage of been more robust (since 1998) and supported the following features (not supported by SIP):

- IPMA;

- VT Advantage;

- 7925 & 7926;

- and others.

 In the future (in the near future for me), SIP will be the only protocol and the old (but excellent) SCCP will not be used anymore ... you can notice that more and more endpoints are supporting only SIP (some examples: SX10, the new IP Phones: 7800 and 8800 series and others) ... because of that, SIP development are extremely intense.

 Now, we are between this two moments, but near the second one (in my opinion).

 If you don't have any old equipment that need SCCP only and you are thinking of protect your investment in the near future, my recommendation is to think in a SIP solution.

 If you have a lot of endpoints using SCCP, my recommendation is to study and plan the migration path to SIP in the near future.

Hope this helps.

[Vivek Batra]

I will definitely agree with Marcelo (+5), SIP will be the only future although with some customization to make non-exclusive features to work.

[john-guy]

I share the same thoughts in terms of Cisco releasing their Video products only using SIP. Also, many third party video clients only support SIP where its up to the End User to perform the protocol or traversal between SIP and H.323.  With many talking about the future with URI dialing is there a benefit deploying all Cisco phones using SIP especially with new installations?  All Voice Calls (Outside-to-Inside the Enterprise) will traverse the VCS-Edge using URI dialing with a conversion to SCCP or H.323 depending on the service.  The feature parity may be a reason to go with SIP or SCCP.  Are you aware of any Cisco Best Practice/Design Guides that lean more toward SIP?