New CME Deployment - SCCP or SIP for phones?

[James Hawkins]

Hi,

I have a CME deployment to do and it is a long time since I touched it so I would like some advice from people who configure it regularly.

The system is going onto a new site and will run on a 2921 ISR G2.

I am planning to go with CME 10.5 unless anyone can give me goods reasons to go to 11.0.

My main question concerns the signalling protocol for IP phones.

These will be a mix of older phones moved form their old CME system and new purchase. The models deployed will be.

• 6921
• 7821
• 7911
• 7941
• 7945
• 7961
• 7965
• 8831
• ATA190

The older phones are the blue coloured ones (currently set up as SCCP) and the new are the red coloured ones.

The 6900 and 7900 phones support SCCP and SIP. The 7821, 8831 and ATA190 support SIP only.

My question is would it be better to configure all the phones using SIP or should I use SCCP where supported and SIP where it is not?

I am really interested in real world experience and gotchas but all input is welcome.

Thanks

James

[Chris Deren]

I would stick with SCCP for the models that support it.

[James Hawkins]

Guys,

Thank you for the responses. I spend most of my time with CUCM where it really does not matter whether phones use SCCP or SIP.

CME is a bit different as the CLI configuration mechanism for SIP and SCCP endpoints is very different. I was wondering whether having one method for all phones might makes things easier.

I am also wondering about things like can an SCCP and SIP phone be in the same hunt group?

I guess I need to spend some time in the lab to do some testing.

[Chris Deren]

There are still some limitations with the SIP phones vs. SCCP. I don't have a comprehensive list, but that should be all documented in the CME Admin Guide. Looking specifically at hunt group configuration there is separate config for SCCP vs SIP which leads me to believe they cannot be part of the same hunt group. Other limitations may be shared lines across devices with different protocols, etc.

http://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucme/admin/configuration/guide/cmeadm/cmecover.html#18789

[James Hawkins]

Hi Chris,

I have found out all about these limitations over the past few days :-)

To anyone who wants an easy life I would stay stick with SCCP phones although that is easier said than done with the newer models.

I have got most things working (bar Extension Mobility on SIP phones) but there is a big feature gap which is really annoying. For instance I wanted to use the bulk speed-dial feature but that only works with SCCP.

James

[Kevin Monteiro]

James,

You can have both  sip andd sccp configured  using "voice hunt group".

-Kevin

[Deepak Rawat]

James, start looking at below threads regarding this discussion while others add their live experience to this:

https://supportforums.cisco.com/discussion/10229286/sip-phones-vs-sccp

https://supportforums.cisco.com/discussion/11993316/what-are-meaningful-advantagesdisadvantages-sip-vs-sccp-phones-cucm-9

Regards

Deepak

[Rob Huffman]

Hi James,

Just wanted to add a reference to the great tips from my friends Chris & Deepak (+5 each!)

You will need to use Voice Hunt groups as shown below (mix of SIP & SCCP);

Ephone-Hunt Groups and Voice Hunt-Groups Comparison

SIP phones support Voice Hunt-Groups. SCCP phones support Ephone-Hunt Groups, and in Cisco Unified CME 4.3 and later versions, SCCP phones also support Voice Hunt-Groups. Table 44-3 compares the features of Ephone-Hunt Groups and Voice Hunt-Groups.

Table 44-3 Feature Comparison of Ephone-Hunt Groups and Voice Hunt-Groups

Feature	Ephone Hunt	Voice Hunt Group
Endpoints Supported	SCCP only	SIP, SCCP, PSTN, and FXS
Parallel Hunt Groups (Call Blast)	No (for alternative, see the “Shared-Line Overlays” section)	Yes
Hunt Statistics Support	Yes	No
B-ACD Support	Yes	No
Features such as present-call and login/logout	Yes	No

From;

http://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucme/admin/configuration/guide/cmeadm/cmecover.html#69788

And you may want to look at the Phone feature guide to compare phone model vs feature;

http://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucme/feature/phone_feature/phone_feature_support_guide.html

Cheers!

Rob

[Vivek Batra]

Hi,

Per my experience, IOS SIP stack is glitchy at least until CME 10 (not sure after that). Working SIP phones with CUCM is far easier than using with CME, not because of easy configuration rather than troubleshooting complexity with CME. It has been sometimes nightmare for me when working on SIP phones with CME. Although SIP is my favorite still I prefer using SCCP if there a choice with me, otherwise as you are on newer version hence I assume there should not be serious issues with SIP as well except here or there.

- Vivek