IMG 1010 - SS7 Diagnostic byte to Reason Header IW

The SS7 REL message is very general. The release of a call could be for a number of different reasons. The REL messages on the SIP side such as BYE, and CANCEL try to narrow down the reason a call was released but in some instances does not give enough information. Feature F-6041 interworks the diagnostics field  information that is embedded in the REL message on the SS7 side and inputs them into the Reason Header's reason-extension field on the SIP side. The feature is enabled or disabled through a field in the SIP_SS7 Interworking object. 

SS7 REL Cause Partial Table from ITU Q.850 Specifications document

Call Flow Diagram

In the call flow diagram below the call is release on the SS7 side with a cause code of User busy and a diagnostic field value of CCBS. With the feature configured, the diagnostic field is mapped and added to the Reason header's Reason Extension field.

Open

Call Trace

Click on link to view the call trace displaying the Reason Header

00:12:14.490 CALL(SIP) (00:00006:00) RCVD INVITE W/SDP from 10.10.1.4:5060 udp CSeq:1
00:12:14.490 CALL(SIP) (00:00006:00)      with Via sent-by: 10.10.1.4
00:12:14.490 CALL(SIP) (00:00006:00)      Call-id: 1-6440@10.10.1.4
00:12:14.490 CALL(SIP) (00:00006:00)      and Msg Size: 565
00:12:14.490 CALL(SIP) (00:00006:00)
                        ---> [10.10.1.4, 5060]
                       INVITE sip:5555@10.10.1.173:5060 SIP/2.0\r\n
                       Via: SIP/2.0/UDP 10.10.1.4:5060;branch=z9hG4bK-6440-1-0\r\n
                       From: sipp <sip:sipp@10.10.1.4:5060>;tag=6440SIPpTag001\r\n
                       To: sut <sip:5555@10.10.1.173:5060>\r\n
                       Call-ID: 1-6440@10.10.1.4\r\n
                       CSeq: 1 INVITE\r\n
                       Contact: sip:sipp@10.10.1.4:5060\r\n
                       Max-Forwards: 70\r\n
                       Diversion: <sip:13216938059@voxbone.com>;counter=1;reason=unknown\r\n
                       Subject: Performance Test\r\n
                       Content-Type: application/sdp\r\n
                       Content-Length:   127\r\n
                       \r\n
                       v=0\r\n
                       o=user1 53655765 2353687637 IN IP4 10.10.1.4\r\n
                       s=-\r\n
                       c=IN IP4 10.10.1.4\r\n
                       t=0 0\r\n
                       m=audio 6000 RTP/AVP 0\r\n
                       a=rtpmap:0 PCMU/8000
00:12:14.490 CALL(SIP) (00:00006:00) SENT 100 Trying to 10.10.1.4:5060
00:12:14.490 CALL(SIP) (00:00006:00)
                        <--- [10.10.1.4, 5060 <- 10.10.1.173, 5060]
                       SIP/2.0 100 Trying\r\n
                       Via: SIP/2.0/UDP 10.10.1.4:5060;branch=z9hG4bK-6440-1-0;received=10.10.1.4\r\n
                       Call-ID: 1-6440@10.10.1.4\r\n
                       From: sipp <sip:sipp@10.10.1.4:5060>;tag=6440SIPpTag001\r\n
                       To: sut <sip:5555@10.10.1.173:5060>\r\n
                       CSeq: 1 INVITE\r\n
                       Server: Dialogic-SIP/10.5.3.105 VINN 0\r\n
                       Content-Length: 0\r\n
                       \r\n
                       
00:12:14.490 CALL(SIP) (00:00006:00) SENT Route Control to L4
00:12:14.490 CALL(L4)  (00:00006:00) RCVD Route Control from SIP
00:12:14.490 CALL(L4)  (00:00006:00) Accessing Route Table 2
00:12:14.490 CALL(L4)  (00:00006:00) Accessing Resource Table 1
00:12:14.490 CALL(L4)  (00:00006:00) Hunting Algorithm is Round Robin
00:12:14.490 CALL(L4)  (00:00006:00) SENT Route Control Ack to SIP
00:12:14.490 CALL(SIP) (00:00006:00) RCVD Route Control Ack from L4
00:12:14.490 CALL(SIP) (00:00006:00) Session Group Profile ID is 1
00:12:14.490 CALL(SIP) (00:00006:00) SENT Route Control to L4
00:12:14.490 CALL(L4)  (00:00006:00) RCVD Route Control from SIP
00:12:14.490 CALL(L4)  (00:00006:00) Accessing IP Bearer Profiles
00:12:14.490 CALL(L4)  (00:00006:00) Profile Id 1 (RG 769)
00:12:14.490 CALL(L4)  (00:00006:00) SENT Route Control Ack to SIP
00:12:14.490 CALL(SIP) (00:00006:00) RCVD Route Control Ack from L4
00:12:14.490 CALL(SIP) (00:00006:00) m line (audio) codec list:  0
00:12:14.490 CALL(SIP) (00:00006:00) RTP Type: 0, name: PCMU, clk: 8000
00:12:14.490 CALL(SIP) (00:00006:00) CODEC Negotiation Priority LOCAL
00:12:14.490 CALL(SIP) (00:00006:00) CPC (Default)
00:12:14.490 CALL(SIP) (00:00006:00) Leg 0 associated with hndl(4994), LTS(1797)(span 4128 chan 5)
00:12:14.490 CALL(SIP) (00:00006:00) SENT Setup to L4
00:12:14.490 CALL(L4)  (00:00006:00) RCVD Setup Ind  from SIP
00:12:14.490 CALL(L4)  (00:00006:00) SENT RFS to GCL
00:12:14.500 CALL(GCL) (00:00006:00) RCVD RFS DN=[5555] ANI=[] from L4
00:12:14.500 CALL(GCL) (00:00006:00) DN NOA=[3]
00:12:14.500 CALL(GCL) (00:00006:00) Incoming Channel Group = 15 [SIP]
00:12:14.500 CALL(GCL) (00:00006:00) SENT Make Call Request to GCL
00:12:14.500 CALL(GCL) (00:00006:01) SENT Route Control to L4
00:12:14.500 CALL(L4)  (00:00006:00) RCVD RFS response  from GCL
00:12:14.500 CALL(L4)  (00:00006:00) RCVD Route Control from GCL
00:12:14.500 CALL(L4)  (00:00006:00) Accessing Route Table 7(m)
00:12:14.500 CALL(GCL) (00:00006:01) RCVD Route Control Ack (Mid Stream Router)from L4
00:12:14.500 CALL(GCL) (00:00006:01) Outgoing Channel Group = 0 [SS71]
00:12:14.500 CALL(GCL) (00:00006:01) SENT Route Control to L4
00:12:14.500 CALL(L4)  (00:00006:01) RCVD Route Control from GCL
00:12:14.500 CALL(L4)  (00:00006:01) Accessing Resource Table 1
00:12:14.500 CALL(L4)  (00:00006:01) Resource Group ID is 32
00:12:14.500 CALL(L4)  (00:00006:01) Hunting Algorithm is ROUND_ROBIN_CLOCKWISE
00:12:14.500 CALL(L4)  (00:00006:01) RCVD Ported Number
00:12:14.500 CALL(L4)  (00:00006:01) IW: Override TMR (03)
00:12:14.500 CALL(L4)  (00:00006:01) IW: Override BC/USI
00:12:14.500 CALL(L4)  (00:00006:01) SENT Outseize Ctrl to SS7
00:12:14.500 CALL(GCL) (00:00006:01) RCVD CPE of ADDRESS INFO from L4
00:12:14.500 CALL(GCL) (00:00006:01) Leg 1 associated with LTS(5)(span 28 chan 5)
00:12:14.500 CALL(SS7) (00:00006:01) RCVD Outseize Ctrl (0x1:0x2:3) from L4
00:12:14.500 CALL(SS7) (00:00006:01)
                       SENT: STK: 0     PRI: 00
                       DPC:  0-0-2      OPC: 0-0-1
                       SLS:  0x03       CIC: 00003 (0x0003)
                       IAM  [0048000a0302000403105555]
00:12:14.500 CALL(SS7) (00:00006:01) SENT IAM to (0x1:0x2:3)
00:12:14.560 CALL(SS7) (00:00006:01)
                       RCVD: STK: 0     PRI: 00
                       DPC:  0-0-1      OPC: 0-0-2
                       SLS:  0x00       CIC: 00003 (0x0003)
                       REL  [0200058091010203]
00:12:14.560 CALL(SS7) (00:00006:01) RCVD REL cause 17 from (0x2:0x1:3)
00:12:14.560 CALL(SS7) (00:00006:01) SENT Clear Req w/info (0x2:0x1:3) to L4
00:12:14.560 CALL(SS7) (00:00006:01)
                       SENT: STK: 0     PRI: 00
                       DPC:  0-0-2      OPC: 0-0-1
                       SLS:  0x03       CIC: 00003 (0x0003)
                       RLC  [00]
00:12:14.560 CALL(SS7) (00:00006:01) SENT RLC to (0x1:0x2:3)
00:12:14.560 CALL(L4)  (00:00006:01) RCVD Clear request  from SS7
00:12:14.560 CALL(L4)  (00:00006:01) SENT Route Control NACK(27) to GCL
00:12:14.560 CALL(GCL) (00:00006:00) SENT Clear Response, cause=17 to L4
00:12:14.560 CALL(L4)  (00:00006:00) RCVD Clear, cause=17 from GCL
00:12:14.560 CALL(L4)  (00:00006:00) SENT Clear Request, cause=17 to SIP
00:12:14.560 CALL(SIP) (00:00006:00) RCVD Clear Request from L4
00:12:14.560 CALL(SIP) (00:00006:00) Call processing released
00:12:14.560 CALL(SIP) (00:00006:00) Reason Hdr: "User busy"
00:12:14.560 CALL(SIP) (00:00006:00) SENT Clear Request to L4
00:12:14.560 CALL(SIP) (00:00006:00) SENT 486 Busy Here [Call processing released] to 10.10.1.4:5060 Cseq:1
00:12:14.560 CALL(SIP) (00:00006:00)
                        <--- [10.10.1.4, 5060 <- 10.10.1.173, 5060]
                       SIP/2.0 486 Busy Here [Call processing released]\r\n
                       Via: SIP/2.0/UDP 10.10.1.4:5060;branch=z9hG4bK-6440-1-0;received=10.10.1.4\r\n
                       Call-ID: 1-6440@10.10.1.4\r\n
                       From: sipp <sip:sipp@10.10.1.4:5060>;tag=6440SIPpTag001\r\n
                       To: sut <sip:5555@10.10.1.173:5060>;tag=a94c095b773be1dd6e8d668a785a9c84da0492b1\r\n
                       Contact: <sip:5555@10.10.1.173:5060>\r\n
                       CSeq: 1 INVITE\r\n
                       Server: Dialogic-SIP/10.5.3.105 VINN 0\r\n
                       Reason: Q.850 ;cause=17 ;text="User busy" ;extension= 01 02 03\r\n
                       Content-Length: 0\r\n
                       \r\n
                       
00:12:14.560 CALL(L4)  (00:00006:00) RCVD Clear request  from SIP
00:12:14.560 CALL(L4)  (00:00006:00) SENT Channel Release w/data to GCL
00:12:14.560 CALL(GCL) (00:00006:00) RCVD Channel Released w/data, cause=17 from L4
00:12:14.560 CALL(GCL) (00:00006:00) Call Duration(sec): 0
00:12:14.570 CALL(SIP) (00:00006:00) RCVD ACK from 10.10.1.4:5060 udp CSeq:1 Msg Size:410
00:12:14.570 CALL(SIP) (00:00006:00)      with Via sent-by: 10.10.1.4 udp
00:12:14.570 CALL(SIP) (00:00006:00)
                        ---> [10.10.1.4, 5060]
                       ACK sip:5555@10.10.1.173:5060 SIP/2.0\r\n
                       Via: SIP/2.0/UDP 10.10.1.4:5060;branch=z9hG4bK-6440-1-0;
                       received=10.10.1.4\r\n
                       From: sipp <sip:sipp@10.10.1.4:5060>;tag=6440SIPpTag001\r\n
                       To: sut <sip:5555@10.10.1.173:5060>;tag=a94c095b773be1dd6e8d668a785a9c84da0492b1\r\n
                       Call-ID: 1-6440@10.10.1.4\r\n
                       CSeq: 1 ACK\r\n
                       Contact: <sip:sipp@10.10.1.4:5060;transport=UDP>\r\n
                       Max-Forwards: 70\r\n
                       Subject: Performance Test\r\n
                       Content-Length: 0\r\n
                       \r\n

Configuration

The procedure below describes the objects that need to be configured for this feature to function. The procedure assumes that all the Basic Configurations such as facilities, network interfaces, profiles, etc have already been configured. Also, since the feature involves SS7, an SS7 stack along with its linkset, links, and routes must be configured before proceeding.

Configure SIP Profile and SIP_SS7 Interworking

• Right click on the Profiles object and select New SIP SGP. Once SIP SGP pane is created, change the SIP Profile ID to something other than '0'. The SIP SGP object with a 0 in the SIP Profile ID field is a default profile and cannot be modified. Once the ID has been modified, the individual fields in the SIP SGP object can be modified. Refer to IMG 1010 - SIP Profile - 10.5.3 topic for more information on configuring the remaining individual fields within this object.

• Right click on the SIP Profile just created and select New SIP_SS7 Interworking. In the object that appears, select Enable from the drop down menu in the REL Diagnostic field to Reason-extension field. This will enable the feature in the SIP Profile object. Refer to the IMG 1010 - Interworking from SIP to ISUP topic for more information on configuring the remaining individual fields in this object.

Configure SIP Signaling

• Right click on the IMG Name physical node object and select New Signaling. The Signaling object is a parent or container object and no configuration is needed here. Refer to the IMG 1010 - Signaling Object topic for more information on this object.

• Right click on the Signaling object and select New SIP. In the Remote IMG's SIP Profile field, select from the drop down menu the SIP Profile created above. Refer to the IMG 1010 - SIP Signaling Object topic for information on configuring the remaining individual fields within this object.

Configure the External Remote Gateway

Configure the information needed to communicate with the remote gateway that will be communicating with the IMG using this feature.

• Right click on the Dialogic IMG EMS object and select New External Network Elements. The External Network Elements object is a parent or container object and no configuration is needed here. Refer to the IMG 1010 - External Network Elements topic for more information on this object.

• Right click on the External Network Elements object and select New External Gateways. Again, the External Gateways object is a parent or container object and no configuration is needed here. Refer to the IMG 1010 - External Gateways topic for more information on this object.

• Right click on the External Gateways object and select New External Gateway. Enter a name that identifies this gateway.

• Select SIP from the drop down menu in the Gateway Signaling Protocol field and enter an IP address that will be used to communicate with this gateway.

• Select from drop down menu of the SIP Profile field, the SIP Profile created above. Refer to the IMG 1010 - External Gateway topic for more information on configuring the remaining individual fields in this object.

Configure SS7 Channel Group

• Right click on the Routing Configuration object and select New Channel Groups. The Channel Groups object is a parent or container object and no configuration is needed here. Refer to the IMG 1010 - Channel Groups topic for more information on this object.

• Right click on the Channel Groups object and select New Channel Group. Enter a name to identify this channel group.

• Select SS7 from the drop down menu in the Signaling Type field.  Refer to the IMG 1010 - Channel Group topic for more information on configuring this object.

• Right click on the Channel Group object and create the ISUP Group. Refer to the IMG 1010 - ISUP Group topic for more information on configuring this object.

• Right click on the ISUP Group object and select New Circuits. Refer to the IMG 1010 - Circuit Group topic for information on configuring the CICs.

Configure SIP Channel Group

• Right click on the Channel Groups object and select New Channel Group. Enter a name to identify this channel group.

• Select SIP from the drop down menu in the Signaling Type field. Refer to the IMG 1010 - Channel Group topic for more information on configuring the individual fields in this object.

• Right click on the SIP channel group created and select New IP Network Element. Select from the drop down menu of the IP Network Element field the remote gateway configured above. Refer to the IMG 1010 - IP Network Element topic for more information on configuring the object.

Configure Routing and Translations

At this point, the feature has been configured along with the SIP and SS7 channel groups. The routing and translation configuration can now be achieved so that the calls are between the two channel groups.

Additional Information

• If the feature is enabled and the IMG receives an SS7 REL message without the diagnostics field embedded, the Reason Extension field will not be populated in the Reason Header.

• Diagnostic information is not available for every cause. In those cases in which the diagnostic is a Q.931 information element, the coding of the diagnostic is the same as for the corresponding information element in clause 4/Q.931.

• When the feature is enabled, the diagnostic field will be included in the outgoing SIP BYE, CANCEL, 4xx, 5xx, and 6xx Reason Header extension field.