SIP w/PRI Handoff Trunk Question

[mkh9]

We have CM 5.2.1 and have 8 PRI with ATT currently. We are doing a test/tune next week for SIP trunk with PRI handoff (NO DID's are being ported at this time, just test number only).
ATT states they have a router they are bringing in with with PRI interface. They stated there will be No interface with our SBC or Session/system manger (we previously purchased for SIP trunking purchase but due to many reasons the actual SIP trunk piece was never completed.)

So Now ATT says the SIP will be brought in on IP but hand off on PRI. It will Plug into a TN464 circuit pack.

I am interpreting this as it's plugging into an existing TN464 - especially because they asked us to be aware there may be down time while they bring up the SIP trunk momentarily.

I am trying to figure out if I need to set up a new trunk in CM for this, I don't think I would but then I don't know for sure and trunks etc. are not my strong suite. Our PBX has been programmed with it's existing trunks/route patterns etc. since before I became the one administering it.

Has anyone brought in ATT's IP Flex product with their PRI Handoff?

Any suggestions or input would be appreciated.

Thank you very much!

 

[DAVIDPAYNE]

I have not hand this service, but I know it is used to get SIP to equipment that normal does not support it. But it should be just what they say it is. I.e. They are running an IP circuit into your location and connecting to there device.
That device will change that IP/SIP circuit into a normal PRI circuit. You might have to make changes to your PRI config to get them connected. YOu would have to work with AT&T during the cut.

But using this setup. your system will not know that the lines are SIP, becasue they will not be as far as the PBX is concerned. That AT&T box will be handling that.

 

[iggy1952]

mkh9,

We have installed AT&T IP Flex circuits using PRI handoffs. AT&T installs the edge router via fiber to your computer room and supplies a crossover cable to your PBX. You should be able to maintain your current trunk and signaling configuration in your CM. I did not have to change any settings in the TN464 ds1 board: esf, b8zs, protocol b, etc. Cutover to the new circuit will require downtime when you plug in the crossover cable to the TN464 board from their router.

Please note that AT&T recently changed from Cisco routers to their Business In A Box (BIB)solution which does not support automatic inbound alternative routing (IAR). We experienced audio issue with one of our locations (choppy audio) which was corrected with a firmware update.

Also note the AT&T BVoIP support is lousy requiring escalation to reach experienced engineers. Make sure you can open tickets via TicketExpress with your new circuit as you will have long wait times calling the toll-free support number.



iggy1952

 

[mkh9]

Thank you both for your input that helps a lot!

I appreciate the information about the trunks,signaling and ds1- I was concerned whether there would be configuration changes needed and I will make sure we have access to the TicketExpress, calling their toll free number is torture for just about anything!!

Thank you both again!

 

[DTDude]

Iggy's pretty much got it. The only thing I would add is that you should expect the PRI to be delivered using the N12 protocol, so if you're using DMS or ESS you may need to change it. I've found the fact that there are multiple PRI protocols to be, well, to put it nicely, unfamiliar to some AT&T techs.

 

[wpetilli]

I guess for minimal changes it sounds good, but isn't one of the main benefits of migrating to SIP trunking the reduction in physical connections?

 

[montyzummer]

This will be cost savings im guessing........bringing up an extra data circuit to support SIP only traffic would be fairly hefty .....AT&T must have decent salesmen and cheap call costs

ACSS (UC/SBCE/SM/SME)

Not that they mean a thing anymore , get a brain dump pass the test crash the system.