Transcoding H.323 to SIP

[peterdonnelly]

Hi folks. I am trying to be a bit of a miserable sod with this one. We have a CS1000 (Belfast) which has some H.323 trunks and a lot more SIP trunks. We are trying to knit together approximately 10 PBX's around Europe over the MPLS. Currently 1 PBX (Dublin) talks to the NRS on our CS1000 using 5 H.323 trunks but as I have been discovering, the rest of the PBXs in the picture have got SIP trunks. Can the CS1000 (Belfast) act as a sort of transcoder where if Dublin needs to talk to another PBX it can "go thru" Belfast and be transcoded into SIP and back out of the Belfast switch to wherever?

It might be more hassle than it's worth just to save a few bob but it would be nice to know if there is an answer.

Thanks for reading.

 

[Triton101]

according to the books it sounds possible.

SUCCESSION 5.x in NTP NN43001-313
IP Peer Networking Installation and Commissioning

page 81(might be diff page if you have a differed PDF version)

titled -H.323-to-SIP signaling

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Find a job you love and you'll never work a day in your life. - Confucius

 

[NortelGuy1979]

I believe so, yes. H323 and SIP are simply signaling - the codecs are both typically still G.711 and G.729, so it's not actually transcoding anything. It's just interpreting the signaling between H323 and SIP, which I believe NRS is capable of.

Matthew - Technical Support Engineer

 

[peterdonnelly]

happy days. Theoretically possible is a challenge. Does that mean that the CS1000 can mediate a call and then step out when the endpoints talk? Or is still going to require a H.323 in/out of the CS1000 and a SIP license in/out of the CS1000 during the call?

 

[Triton101]

Virtual Trunks (SIP licenses and H.323 licenses) will be eaten up for the time of the call:

System A: H.323 Trunk only 1 license

System B: H.323 and SIP Trunk 2 licenses (1 for h.323 and 1 for sip)

System C: SIP Trunk Only 1 License

so in the above scenario system A wants to call system C but has to use system B to be the gateway between H.323 and SIP.

It sounds like the NRS does the decision making. but for 1 call you would be eating up 4 licenses......

__________________________________________________________
Find a job you love and you'll never work a day in your life. - Confucius

 

[peterdonnelly]

I thought as much. But I am very happy with all the responses. Thanks very much. I am as ever grateful to have such friendly responses.

 

[allenmac]

I am in the same situation, I have systems that have only H.323, and systems that have only SIP, and my HQ has both.

I have configured the HQ endpoint in NRS with a default route for CDP and UDP call types. This causes calls from a system with H.323 (or SIP) trying to call another system with different virtual trunk types to tandem through the system with both types, and the transcoding is automatic.

This is a 5 minute fix for your situation.

I have had this working for years.

 

[peterdonnelly]

I am getting so much good information todaqy. this is all great. I am seriously gonna get cracking on this. Time to skill up on NRS etc.