We have a customer who uses a SIP trunk for PSTN connectivity with a Cisco Voice Gateway.
IP Phone -----> CUCM ---SIPTrunk--> CUBE ---SIPTrunk---> PSTN Provider
There's a issue where organization cannot make more than 3 concurrent outgoing calls. SIP Trunk has 30 Sessions allowed from Service Provider Side. It was working without an issue for more than one year and suddenly this issue came up. When I looked into gateway SIP traces, I noticed following;
Cube receives Invite from CUCM
*Sep 12 13:05:15.318: //-1/xxxxxxxxxxxx/SIP/Msg/ccsipDisplayMsg:
Received:
INVITE sip:1090773842920@10.8.43.231:5060 SIP/2.0
Via: SIP/2.0/UDP 10.1.140.1:5060;branch=z9hG4bK5a228115041dbe
From: "MALINDA DIAS" <sip:68819@10.1.140.1>;tag=33143171~448cfc3a-4ede-45f4-aca8-9641915fba54-64047908
To: <sip:1090773842920@10.8.43.231>
Date: Thu, 12 Sep 2019 12:46:10 GMT
Call-ID: 4a76da80-d7a13e12-53a06e-18c010a@10.1.140.1
Supported: timer,resource-priority,replaces
Min-SE: 900
User-Agent: Cisco-CUCM10.5
Allow: INVITE, OPTIONS, INFO, BYE, CANCEL, ACK, PRACK, UPDATE, REFER, SUBSCRIBE, NOTIFY
CSeq: 101 INVITE
Expires: 180
Allow-Events: presence, kpml
Supported: X-cisco-srtp-fallback,X-cisco-original-called
Call-Info: <sip:10.1.140.1:5060>;method="NOTIFY;Event=telephone-event;Duration=500"
Call-Info: <urn:x-cisco-remotecc:callinfo>;x-cisco-video-traffic-class=DESKTOP
Cisco-Guid: 1249303168-0000065536-0000241771-0025952522
Session-Expires: 1800
P-Asserted-Identity: "MALINDA DIAS" <sip:68819@10.1.140.1>
Remote-Party-ID: "MALINDA DIAS" <sip:68819@10.1.140.1>;party=calling;screen=yes;privacy=off
Contact: <sip:68819@10.1.140.1:5060>;+u.sip!devicename.ccm.cisco.com="SEPC4B9CD819ADD"
Max-Forwards: 69
Content-Type: application/sdp
Content-Length: 350
v=0
o=CiscoSystemsCCM-SIP 33143171 1 IN IP4 10.1.140.1
s=SIP Call
c=IN IP4 10.8.26.20
b=TIAS:64000
b=AS:64
t=0 0
m=audio 29338 RTP/AVP 0 8 116 18 101
b=TIAS:64000
a=rtpmap:0 PCMU/8000
a=rtpmap:8 PCMA/8000
a=rtpmap:116 iLBC/8000
a=maxptime:20
a=fmtp:116 mode=20
a=rtpmap:18 G729/8000
a=rtpmap:101 telephone-event/8000
a=fmtp:101 0-15
Cube Sends invite towards PSTN Provider with out RTP port mentioned
*Sep 12 13:05:15.338: //1190571/4A76DA800003/SIP/Msg/ccsipDisplayMsg:
Sent:
INVITE sip:0773842920@172.16.2.1:5060 SIP/2.0
Via: SIP/2.0/UDP 10.8.43.231:5060;branch=z9hG4bK4237622AB
From: "MALINDA DIAS" <sip:112990000@172.16.1.1>;tag=D1239FF8-87A
To: <sip:0773842920@172.16.2.1>
Date: Thu, 12 Sep 2019 13:05:15 GMT
Call-ID: CBF134D6-D49411E9-B85A81D1-69F88A34@10.8.43.231
Supported: 100rel,timer,resource-priority,replaces,sdp-anat
Min-SE: 1800
Cisco-Guid: 1249303168-0000065536-0000241771-0025952522
User-Agent: Cisco-SIPGateway/IOS-12.x
Allow: INVITE, OPTIONS, BYE, CANCEL, ACK, PRACK, UPDATE, REFER, SUBSCRIBE, NOTIFY, INFO, REGISTER
CSeq: 101 INVITE
Timestamp: 1568293515
Contact: <sip:112990000@10.8.43.231:5060>
Expires: 180
Allow-Events: telephone-event
Max-Forwards: 68
Session-Expires: 1800
Content-Type: application/sdp
Content-Disposition: session;handling=required
Content-Length: 346
v=0
o=CiscoSystemsSIP-GW-UserAgent 394 794 IN IP4 10.8.43.231
s=SIP Call
c=IN IP4 10.8.43.231
t=0 0
m=audio 0 RTP/AVP 0 8 18 100 101
c=IN IP4 10.8.43.231
a=rtpmap:0 PCMU/8000
a=rtpmap:8 PCMA/8000
a=rtpmap:18 G729/8000
a=fmtp:18 annexb=no
a=rtpmap:100 X-NSE/8000
a=fmtp:100 192-194
a=rtpmap:101 telephone-event/8000
a=fmtp:101 0-16
PSTN Provider rejects call
*Sep 12 13:05:15.362: //1190571/4A76DA800003/SIP/Msg/ccsipDisplayMsg:
Received:
SIP/2.0 480 Temporarily Unavailable
Via: SIP/2.0/UDP 10.8.43.231:5060;branch=z9hG4bK4237622AB
Call-ID: CBF134D6-D49411E9-B85A81D1-69F88A34@10.8.43.231
From: "MALINDA DIAS"<sip:112990000@172.16.1.1>;tag=D1239FF8-87A
To: <sip:0773842920@172.16.2.1>;tag=16010209-ZAJ01ae209672a
CSeq: 101 INVITE
User-Agent: ZTE Softswitch/1.0.0
Reason: Q.850;cause=34;text="Resource unavailable"
Content-Length: 0
PSTN Provider states they don't receive a RTP port in initial invite so they reject it from their side. We did not make any recent changes also. Can any one advice on this ? For first 3 calls everything works fine, from 4th call onwards, call is rejected. Please advice.
CUBE Details
CISCO3825
IOS - flash:c3825-spservicesk9-mz.151-4.M7.bin
