dhailey13 wrote:
.... "newer must be better".
Hailey
That's funny to me as I think that SIP and SCCP are roughly the same age. Actually, SIP may be a little older if you go back to its beginnings.
Anyway, I agree with Big H on this one (+5 to my brother Hailey). All things being equal, I go with SCCP for Unity integration.
Actually, this reminds me of a certain customer in California that asked us the same exact question. I believe the response NetCraftsmen provided at that time would still hold true, though I have not researched CUC 8.x to any depth. I'll paraphrase to protect the innocent:
As to the broader topic of why NetCraftsmen still leads with SCCP in our CUC-CUCM design template I can tell you that Hailey and I reconsider SIP vs. SCCP on every new release of CUCM/CUC/Unity and any project using these new releases. We still settle on SCCP for the time being. In general, they are basically equal with only a few considerations with SIP, including:
1. With SIP, you can’t have MoH play out to a caller when CUC is performing a transfer. The weight of this depends on how you want to use CUC. An example we had with a customer is that for their automated attendants they wanted to play marketing music while they tried to transfer a call to a user. In this particular case, that customer had calls hunt all over God’s creation for a human being and they didn’t want the caller listening ring back during the hunt. So, if MoH play out on transfers isn’t important to a customer then this isn’t a big deal. From a design team’s perspective, requirements like the one I describe above aren’t discovered until an end user says “hey, can we…”. So, we like to have the option of saying yes to that question.
2. According to the CUC SIP integration guide (7.1x) there is a little blurb that “best practice” is to have all stations running SIP if CUC is SIP integrated. The reason for a statement like this is that if you have any phone stations/gateways/etc. that do not support RFC-2833 for DTMF then you must enable a MTP on the CUC SIP trunk to allow calls originating from or going through these stations to interact with the IVR menu on CUC (e.g. logging in, automated attendant, etc.). Cisco phones that don’t support RFC-2833 include: 7902G, 7905G, 7910G, 7912G, VoWLAN phones, and 7985. If you are using these stations then you may need to leverage MTP resources on the CUC SIP trunk and take a second look at your media resource design/allocation.
In addition to these items, the other considerations Hailey and I apply to our recommendation are based on experience. It isn’t that SIP is bad or that SCCP is better. You can actually run both on CUC. In the example I am thinking of, we ran SIP for TIMG/PIMG integration and SCCP for CUCM integration. We have just found SCCP to be a more mature protocol stack in Cisco-land and why go looking for software bugs when they already have an easy enough time finding you?
Oh, BTW just in case you were curious, using CUC with SCCP does not mean you can’t have SIP phones. CUC supports RFC-2833 in SCCP or SIP mode. I have tested this out a few times and we have customers that use a mixture of SCCP/SIP phones and SCCP on Unity VM.
I think that about covers the NetCraftsmen position on SIP vs. SCCP. Granted, we are just one small voice in a sea of talented Cisco engineers. Well, actually Hailey has quite a big voice. Go Great ..er Big.. Escape!
HTH.
Regards,
Bill
