Hi,
I have few customers running with derived trunks model with one SBC. For example customer1.mysbcdr.com and customer2.mysbcdr.com and so on.
headers look like this in SBC to Teams calling
INVITE sip:+61111111111@sip2.pstnhub.microsoft.com:5061 SIP/2.0
Via: SIP/2.0/TLS 1.1.1.1:5060;branch=z9hG4bK00B49c8ccc42a55718c
From: "Test User" <sip:2222@customer1.mysbccdr.com>;tag=gK005d1f86
To: <sip:+61111111111@sip2.pstnhub.microsoft.com>
Call-ID: 16777374_93010395@1.1.1.1
CSeq: 706946 INVITE
Max-Forwards: 70
Allow: INVITE,ACK,CANCEL,BYE,REFER,NOTIFY,PRACK,OPTIONS,X-MS-Location
Accept: application/sdp, application/isup, application/dtmf, application/dtmf-relay, multipart/mixed
Contact: "Test User" <sip:2222@customer1.mysbccdr.com:5061;transport=tls>
Now that we have new SBC and want to failover to it if first SBC fails for. One obvious solution is to create fqdn like customer1-2.mysbccdr.com in customer1.mysbccdr.com tenancy and put that customer1-2.mysbccdr.com in contact header, that works perfectly. Where customer1-2.mysbccdr.com is resolved to secondary SBC IP address.
Problem is its not easy to go in to each tenancy as there are 100s of them , asking for access and automating through API can be complex process so we are looking for some easier process for example if I create single fqdn secondary.mysbccdr.com and try to put that in contact header that does not work either. Where secondary.mysbccdr.com is resolved to Secondary SBC IP address.
INVITE sip:+61111111111@sip2.pstnhub.microsoft.com:5061 SIP/2.0
Via: SIP/2.0/TLS 1.1.1.1:5060;branch=z9hG4bK00B49c8ccc42a55718c
From: "Test User" <sip:2222@customer1.mysbccdr.com>;tag=gK005d1f86
To: <sip:+61111111111@sip2.pstnhub.microsoft.com>
Call-ID: 16777374_93010395@1.1.1.1
CSeq: 706946 INVITE
Max-Forwards: 70
Allow: INVITE,ACK,CANCEL,BYE,REFER,NOTIFY,PRACK,OPTIONS,X-MS-Location
Accept: application/sdp, application/isup, application/dtmf, application/dtmf-relay, multipart/mixed
Contact: "Test User" <sip:2222@secondary.mysbccdr.com:5061;transport=tls>
I tried to use original headers as in first SBC in secondary SBC , calls connect but subsequent request such as BYE from MS Teams does not come to secondary SBC , obviously because fqdn is still resolving to primary SBC.
In short we are failing over from PBX -> SBC1->Teams to PBX -> SBC2 -> Teams but we cannot have new fqdn added as a domain in existing tenancies and we cannot change DNS entries. Is there any workaround solution.
