[SR-Users] No ACK from MS Teams

Thu Feb 11 09:20:52 CET 2021

Try to put SBC-FQDN instead of SBC-IP-ADDR in the Record-Route:

Record-Route: <sip:*SBC-FQDN*
:5060;ftag=c3da9477e05d45fca31c24a155af3318;lr=on>

On Thu, 11 Feb 2021 at 08:32, Phillman25 Kyriacou <phillman25 at gmail.com>
wrote:

> Dear List
>
> Hope this email finds you all well.
>
> I have followed the below tutorial on how to integrate Kamailio with MS
> Teams
>
> https://skalatan.de/en/blog/kamailio-sbc-teams
>
> However i have been facing an issue with MS Teams with direct routing
> where MS Teams does not send back an ACK after a 200 OK.
>
> The current inbound call flow is the following:
>
> *MS Teams ==> Kamailio==>Asterisk*
>
> Once Asterisk answers with 200 OK we send this 200 OK back to MS Teams
> however, MS Teams just doesn't answer back with ACK and call drops.
>
> The below trace shows the INVITE coming from MS Teams and the 200 OK we
> send back.
>
>
> ||||||||||||||||||||
> ====================
> tag: rcv
> pid: 26135
> process: 23
> time: 1613025911.983278
> date: Thu Feb 11 08:45:11 2021
> proto: tls ipv4
> srcip: 52.114.132.46
> srcport: 4352
> dstip: SBC_IP_ADDR
> dstport: 5061
> ~~~~~~~~~~~~~~~~~~~~
> INVITE sip:+357XXXXXXXX at SBC-FQDN:5061;user=phone;transport=tls SIP/2.0
> FROM: Phillip Kyriacou<sip:+357XXXXXXXX at sip.pstnhub.microsoft.com:5061
> ;user=phone>;tag=c3da9477e05d45fca31c24a155af3318
> TO: <sip:+357XXXXXXXX at SBC-FQDN:5061;user=phone>
> CSEQ: 1 INVITE
> CALL-ID: 9cb9a2f3144e594c87bccda76791c28e
> MAX-FORWARDS: 70
> VIA: SIP/2.0/TLS 52.114.132.46:5061;branch=z9hG4bK0cf2c45
> RECORD-ROUTE: <sip:sip-du-a-us.pstnhub.microsoft.com:5061
> ;transport=tls;lr>
> CONTACT: <sip:api-du-b-euwe.pstnhub.microsoft.com:443
> ;x-i=6e5254d9-79c2-4657-b54b-68791aa8e81f;x-c=9cb9a2f3144e594c87bccda76791c28e/d/10/e21a
> 6ff7125e4cbd91e75ec687fd4c5d>
> CONTENT-LENGTH: 1097
> MIN-SE: 300
> SUPPORTED: timer
> USER-AGENT: Microsoft.PSTNHub.SIPProxy v.2021.2.9.1 i.USEA.7
> CONTENT-TYPE: application/sdp
> ALLOW: INVITE,ACK,OPTIONS,CANCEL,BYE,NOTIFY
> SESSION-EXPIRES: 3600
>
> v=0
> o=- 170239 0 IN IP4 127.0.0.1
> s=session
> c=IN IP4 52.113.40.94
> b=CT:10000000
> t=0 0
> m=audio 51414 RTP/SAVP 104 9 103 111 18 0 8 97 101 13 118
> c=IN IP4 52.113.40.94
> a=rtcp:51415
> a=ice-ufrag:BwFs
> a=ice-pwd:sFyvnfQ9iH101E80ZKjCxi9+
> a=rtcp-mux
> a=candidate:1 1 UDP 2130706431 52.113.40.94 51414 typ srflx raddr
> 10.0.137.19 rport 51414
> a=candidate:1 2 UDP 2130705918 52.113.40.94 51415 typ srflx raddr
> 10.0.137.19 rport 51415
> a=candidate:2 1 tcp-act 2121006078 52.113.40.94 49152 typ srflx raddr
> 10.0.137.19 rport 49152
> a=candidate:2 2 tcp-act 2121006078 52.113.40.94 49152 typ srflx raddr
> 10.0.137.19 rport 49152
> a=label:main-audio
> a=mid:1
> a=crypto:1 AES_CM_128_HMAC_SHA1_80
> inline:Igc2LVM9FH5kQtkRpHw99H5SB7Rd7eKzJy4gdWJg|2^31
> a=sendrecv
> a=rtpmap:104 SILK/16000
> a=rtpmap:9 G722/8000
> a=rtpmap:103 SILK/8000
> a=rtpmap:111 SIREN/16000
> a=fmtp:111 bitrate=16000
> a=rtpmap:18 G729/8000
> a=fmtp:18 annexb=no
> a=rtpmap:0 PCMU/8000
> a=rtpmap:8 PCMA/8000
> a=rtpmap:97 RED/8000
> a=rtpmap:101 telephone-event/8000
> a=fmtp:101 0-16
> a=rtpmap:13 CN/8000
> a=rtpmap:118 CN/16000
> a=ptime:20
>
> ||||||||||||||||||||
> ====================
> tag: snd
> pid: 26086
> process: 6
> time: 1613025917.726664
> date: Thu Feb 11 08:45:17 2021
> proto: tls ipv4
> srcip: SBC_IP_ADDR
> srcport: 5061
> dstip: 52.114.132.46
> dstport: 5061
> ~~~~~~~~~~~~~~~~~~~~
> SIP/2.0 200 OK
> Via: SIP/2.0/TLS 52.114.132.46:5061;branch=z9hG4bK0cf2c45
> Record-Route:
> <sip:SBC-IP-ADDR:5060;ftag=c3da9477e05d45fca31c24a155af3318;lr=on>
> Record-Route:
> <sip:SBC-FQDN:5061;transport=tls;ftag=c3da9477e05d45fca31c24a155af3318;lr=on>
> Record-Route: <sip:sip-du-a-us.pstnhub.microsoft.com:5061
> ;transport=tls;lr>
> From: Phillip Kyriacou<sip:+357XXXXXXX at sip.pstnhub.microsoft.com:5061
> ;user=phone>;tag=c3da9477e05d45fca31c24a155af3318
> To: <sip:+357XXXXXXXX at SBC-FQDN:5061;user=phone>;tag=as659924a4
> Call-ID: 9cb9a2f3144e594c87bccda76791c28e
> CSeq: 1 INVITE
> Server: MediaGW V1.0
> Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, SUBSCRIBE, NOTIFY, INFO,
> PUBLISH, MESSAGE
> Supported: replaces, timer
> Session-Expires: 1800;refresher=uas
> Contact: <sip:357XXXXXXXX at ASTERISK_PUBLIC_IP:5060>
> Content-Type: application/sdp
> Require: timer
> Content-Length: 339
>
> v=0
> o=root 411266324 411266324 IN IP4 ASTERISK_PUBLIC_IP
> s=ASTERISK
> c=IN IP4 ASTERISK_PUBLIC_IP
> t=0 0
> m=audio 14416 RTP/SAVP 0 8 101
> a=crypto:1 AES_CM_128_HMAC_SHA1_80
> inline:9PcaAGjbemJKTERlFTcVwmLRQoDSEQPxX0L1a6RF
> a=rtpmap:0 PCMU/8000
> a=rtpmap:8 PCMA/8000
> a=rtpmap:101 telephone-event/8000
> a=fmtp:101 0-16
> a=maxptime:150
> a=sendrecv
> ||||||||||||||||||||
>
>
> Am I doing anything wrong here that MS Teams wont respond to my 200 OK?
> The Kamailio SBC is showing active on MS Teams and Kamailio dispatcher
> shows all the MS Team hubs as AP. I also can't see any errors in the log
> file
>
> My TLS cfg has the following:
> ======================
>
>
>
>
>
>
>
>
> *[server:default]method = TLSv1.2+verify_certificate =
> yesrequire_certificate = yesprivate_key =
> /etc/letsencrypt/live/sbc.intelligentsupport.eu/privkey.pem
> <http://sbc.intelligentsupport.eu/privkey.pem>certificate =
> /etc/letsencrypt/live/sbc.intelligentsupport.eu/fullchain.pem
> <http://sbc.intelligentsupport.eu/fullchain.pem>ca_list =
> /etc/ssl/certs/ca-certificates.crt*
>
>
>
>
>
>
> *[client:default]method = TLSv1.2+verify_certificate =
> yesrequire_certificate = yesprivate_key =
> /etc/letsencrypt/live/sbc.intelligentsupport.eu/privkey.pem
> <http://sbc.intelligentsupport.eu/privkey.pem>certificate =
> /etc/letsencrypt/live/sbc.intelligentsupport.eu/fullchain.pem
> <http://sbc.intelligentsupport.eu/fullchain.pem>ca_list =
> /etc/ssl/certs/ca-certificates.crt*
>
>
> Thanks very much in advance!
>
> Phillip
>
>
>
>
> _______________________________________________
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> sr-users at lists.kamailio.org
> https://lists.kamailio.org/cgi-bin/mailman/listinfo/sr-users
>
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