Map ISDN Call Proceeding to SIP 183

Owned by Kelli Higdon
Last updated: Apr 02, 2024
20 min read

 

With the introduction of the MAP ISDN Call Proceeding to SIP 183 functionality, the Call Proceeding message from the ISDN side will be interworked into a 183 Session Progress with SDP message when the value of the Progress Indicator parameter in the Call Proceeding message is either "1" or "8". By interworking these parameters, an early voice path can be established so the caller can hear a prompt played by the terminating endpoint. If no progress indicator is present or the value of the ISDN Progress Indicator is not "1" or "8" then the call will proceed as normal. The Call Proceeding message will be dropped and no SIP 183 Session Progress will be sent. Refer to the information below for more information.

Call Flow Diagrams

Example 1 - Receiving ISDN Progress after CALL PROCEEDING

  • The IMG 2020 receives a SIP INVITE from SIP network and sends the SETUP message to the ISDN network.

  • The IMG 2020 receives a CALL PROCEEDING with Progress Indicator No. 1 or No. 8. The IMG 2020 will send 183 Progress message back to the SIP network and a voice path is established. The Caller from the SIP network can hear the prompt being played from the ISDN side.

  • On receipt of ISDN PROGRESS message with Progress Indicator No.1 or No.8, the IMG 2020 will send another 183 Session Progress with SDP back to the SIP network and caller will continue to hear the prompt which is sent from the ISDN network.

  • The IMG 2020 then receives the ISDN CONNECT message and sends a 200 OK back to SIP network. 


Example 2 - Receiving ISDN CONNECT after CALL PROCEEDING

  • The IMG 2020 receives a SIP INVITE from the SIP network and sends a SETUP message to the ISDN network.

  • The IMG 2020 receives a CALL PROCEEDING with Progress Indicator No. 1 or No. 8. The IMG 2020 will send 183 Progress message back to SIP network and voice path is established. The Caller from the SIP network can hear the prompt being played from the ISDN side.

  • The IMG 2020 then receives the ISDN CONNECT message and sends a 200 OK back to the SIP network.

 

Example 3 - Receiving ISDN ALERTING after CALL PROCEEDING

  • The IMG 2020 receives a SIP INVITE from SIP network and sends the SETUP message to the ISDN network.

  • The IMG 2020 receives a CALL PROCEEDING with Progress Indicator No. 1 or No. 8. The IMG 2020 will send 183 Progress message back to SIP network and voice path is established. The Caller from the SIP network can hear the prompt being played from the ISDN side.

  • On receipt of an ALERTING message, the IMG 2020 will not send any message back to the SIP network and the caller will continue to hear the same ring back tone.

  • The IMG 2020 then receives the ISDN CONNECT message and sends a 200 OK back to SIP network.

 

Example 4 - Receiving ISDN CALL PROCEEDING

  • The IMG 2020 receives a SIP INVITE from the SIP network and sends a SETUP message to the ISDN network.

  • The IMG 2020 receives a CALL PROCEEDING without any Progress Indicator or the Progress Indicator is not No.1 or No.8. The IMG 2020 will not send any message back to the SIP network

  • On receipt of the ISDN ALERTING message, the IMG 2020 will send a 180 Ringing back to the SIP side.

  • On receipt of the ISDN CONNECT message, the IMG 2020 sends a 200 OK back to the SIP network. 


Call Trace

Below is Call trace of functionality with the Call Proceeding messaging highlighted.

06:01:04.159 CALL(SIP) (22:00002:00) RCVD INVITE W/SDP from 10.129.47.146:5060 udp CSeq:1 06:01:04.159 CALL(SIP) (22:00002:00) with Via sent-by: 10.129.47.146 06:01:04.159 CALL(SIP) (22:00002:00) Call-id: 6354@10.129.47.146 06:01:04.159 CALL(SIP) (22:00002:00) and Msg Size: 525 06:01:04.159 CALL(SIP) (22:00002:00) ---> [10.129.47.146, 5060] INVITE sip:5088628562@10.129.47.165 SIP/2.0\r\n Via: SIP/2.0/UDP 10.129.47.146:5060;branch=z9hG4bK2f680b 0-e89fcc28\r\n From: 12345678 <sip:5088623613@10.129.47.146>;tag=794730 195\r\n To: <sip:5088628562@10.129.47.165>\r\n Call-ID: 6354@10.129.47.146\r\n CSeq: 1 INVITE\r\n Contact: <sip:5088623613@10.129.47.146>\r\n Max-Forwards: 70\r\n Supported: 100rel\r\n Content-Length: 135\r\n Content-Type: application/sdp\r\n \r\n v=0\r\n o=- 2890844526 1310364065 IN IP4 10.129.47.146\r\n s=-\r\n c=IN IP4 10.129.47.146\r\n t=0 0\r\n m=audio 6000 RTP/AVP 0\r\n a=rtpmap:0 PCMU/8000\r\n 06:01:04.159 CALL(SIP) (22:00002:00) SENT 100 Trying to 10.129.47.146:5060 06:01:04.159 CALL(SIP) (22:00002:00) <--- [10.129.47.146, 5060 <- 10.129.47.165, 5060] SIP/2.0 100 Trying\r\n Via: SIP/2.0/UDP 10.129.47.146:5060;branch=z9hG4bK2f680b 0-e89fcc28;received=10.129.47.146\r\n Call-ID: 6354@10.129.47.146\r\n From: 12345678 <sip:5088623613@10.129.47.146>;tag=794730 195\r\n To: <sip:5088628562@10.129.47.165>\r\n CSeq: 1 INVITE\r\n Server: Dialogic-SIP/10.5.3.270 IMG_F 22\r\n Content-Length: 0\r\n \r\n 06:01:04.159 CALL(SIP) (22:00002:00) SENT Route Control to L4 06:01:04.159 CALL(L4) (22:00002:00) RCVD Route Control from SIP 06:01:04.159 CALL(L4) (22:00002:00) Accessing Route Table 2 06:01:04.159 CALL(L4) (22:00002:00) Accessing Resource Table 1 06:01:04.159 CALL(L4) (22:00002:00) Hunting Algorithm is Round Robin 06:01:04.159 CALL(L4) (22:00002:00) SENT Route Control Ack to SIP 06:01:04.159 CALL(SIP) (22:00002:00) RCVD Route Control Ack from L4 06:01:04.159 CALL(SIP) (22:00002:00) Session Group Profile ID is 1 06:01:04.159 CALL(SIP) (22:00002:00) SENT Route Control to L4 06:01:04.159 CALL(L4) (22:00002:00) RCVD Route Control from SIP 06:01:04.159 CALL(L4) (22:00002:00) Accessing IP Bearer Profiles 06:01:04.159 CALL(L4) (22:00002:00) Profile Id 1 (RG 769) 06:01:04.159 CALL(L4) (22:00002:00) SENT Route Control Ack to SIP 06:01:04.159 CALL(SIP) (22:00002:00) RCVD Route Control Ack from L4 06:01:04.159 CALL(SIP) (22:00002:00) m line (audio) codec list: 0 06:01:04.159 CALL(SIP) (22:00002:00) RTP Type: 0, name: PCMU, clk: 8000 06:01:04.159 CALL(SIP) (22:00002:00) CODEC Negotiation Priority LOCAL 06:01:04.159 CALL(SIP) (22:00002:00) CPC (Default) 06:01:04.159 CALL(SIP) (22:00002:00) Leg 0 associated with hndl(4998), LTS(1025)(span 5504 chan 1) 06:01:04.159 CALL(SIP) (22:00002:00) SENT Setup to L4 06:01:04.159 CALL(L4) (22:00002:00) RCVD Setup Ind from SIP 06:01:04.159 CALL(L4) (22:00002:00) SENT RFS to GCL 06:01:04.159 CALL(GCL) (22:00002:00) RCVD RFS DN=[5088628562] ANI=[5088623613]from L4 06:01:04.159 CALL(GCL) (22:00002:00) ANI APRI=[0],SI=[0],Category=[10] 06:01:04.159 CALL(GCL) (22:00002:00) DN NOA=[3] 06:01:04.169 CALL(GCL) (22:00002:00) Incoming Channel Group = 15 [SIP] 06:01:04.169 CALL(GCL) (22:00002:00) SENT Make Call Request to GCL 06:01:04.169 CALL(GCL) (22:00002:01) SENT Route Control to L4 06:01:04.169 CALL(L4) (22:00002:00) RCVD RFS response from GCL 06:01:04.169 CALL(L4) (22:00002:00) RCVD Route Control from GCL 06:01:04.169 CALL(L4) (22:00002:00) Accessing Route Table 5 06:01:04.169 CALL(GCL) (22:00002:01) RCVD Route Control Ack (Mid Stream Router)from L4 06:01:04.169 CALL(GCL) (22:00002:01) Outgoing Channel Group = 0 [ISDN] 06:01:04.169 CALL(GCL) (22:00002:01) SENT Route Control to L4 06:01:04.169 CALL(L4) (22:00002:01) RCVD Route Control from GCL 06:01:04.169 CALL(L4) (22:00002:01) Accessing Resource Table 1 06:01:04.169 CALL(L4) (22:00002:01) Resource Group ID is 32 06:01:04.169 CALL(L4) (22:00002:01) Hunting Algorithm is ROUND_ROBIN_CLOCKWISE 06:01:04.169 CALL(L4) (22:00002:01) IW: Override BC/USI 06:01:04.169 CALL(L4) (22:00002:01) SENT Outseize Ctrl to ISDN 06:01:04.169 CALL(GCL) (22:00002:01) RCVD CPE of ADDRESS INFO from L4 06:01:04.169 CALL(GCL) (22:00002:01) Leg 1 associated with LTS(2)(span 28 chan1) 06:01:04.169 CALL(ISD) (22:00002:01) RCVD Outseize Ctrl from L4 06:01:04.249 CALL(ISD) (22:00002:01) SENT Setup to Network 06:01:04.259 CALL(ISD) (22:00002:01) RCVD Call Proceeding from Network 06:01:04.259 CALL(ISD) (22:00002:01) SENT Outseize Ack to L4 06:01:04.259 CALL(ISD) (22:00002:01) SENT Cut Thru to L4 06:01:04.259 CALL(L4) (22:00002:01) RCVD Call Proceeding from ISDN 06:01:04.259 CALL(L4) (22:00002:01) RCVD Outseize ACK from ISDN 06:01:04.259 CALL(L4) (22:00002:01) RCVD Cut Thru from ISDN 06:01:04.259 CALL(GCL) (22:00002:00) SENT Connect w/Pad Response to L4 06:01:04.259 CALL(L4) (22:00002:01) SENT CutThru to L4 06:01:04.259 CALL(L4) (00:00000:00) IW: CALL PROCEEDING --> 183 Progress 06:01:04.259 CALL(L4) (00:00000:00) IW: progress indicator (8) 06:01:04.259 CALL(L4) (22:00002:00) SENT Progress to SIP 06:01:04.259 CALL(L4) (00:00000:00) IW: CALL PROCEEDING --> 183 Progress 06:01:04.259 CALL(L4) (22:00002:00) SENT connect_1way: r_ts=0x2 l_ts=0x401 to TSI 06:01:04.259 CALL(L4) (22:00002:01) SENT connect_1way: r_ts=0x401 l_ts=0x2 to TSI 06:01:04.259 CALL(SIP) (22:00002:00) RCVD Progress from L4 06:01:04.259 CALL(SIP) (22:00002:00) Set media src IP 10.129.47.166:8004 06:01:04.259 CALL(SIP) (22:00002:00) Set media dst IP 10.129.47.146:6000 06:01:04.259 CALL(SIP) (22:00002:00) CODEC Negotiation Priority LOCAL 06:01:04.259 CALL(SIP) (22:00002:00) Set media PLD ID 2 06:01:04.259 CALL(SIP) (22:00002:00) Set media PLD Size 20, Multiplier:4 06:01:04.259 CALL(SIP) (22:00002:00) RFC 2833 DTMF Relay Disabled,method=0 06:01:04.259 CALL(SIP) (22:00002:00) Set Fax Type to Bypass 06:01:04.259 CALL(SIP) (22:00002:00) Source Port Validation : Enabled 06:01:04.259 CALL(SIP) (22:00002:00) SENT L3-L3 Outseize Ctrl to VPPL 06:01:04.259 CALL(IP) (22:00002:00) RCVD Outseize ([vts 1] [m0.1.1]) from L3P(span 5504 chan 1) 06:01:04.259 CALL(IP) (22:00002:00) RTP: (Src) 10.129.47.166:8004 06:01:04.259 CALL(IP) (22:00002:00) RTP: (Dst) 10.129.47.146:6000 06:01:04.269 CALL(IP) (22:00002:00) VoIP Codec is G711Mulaw; Payload Size is 20 ms 06:01:04.269 CALL(IP) (22:00002:00) Fax Mode is Bypass, Modem Mode is Bypass 06:01:04.289 CALL(IP) (22:00002:00) SENT Outseize ACK (toPvid: x66) to L3P 06:01:04.289 CALL(SIP) (22:00002:00) RCVD Outseize Ack from VPPL 06:01:04.289 CALL(SIP) (22:00002:00) SENT 183 Session Progress W/SDP to 10.129.47.146:5060 UDP 06:01:04.289 CALL(SIP) (22:00002:00) <--- [10.129.47.146, 5060 <- 10.129.47.165, 5060] SIP/2.0 183 Session Progress\r\n Via: SIP/2.0/UDP 10.129.47.146:5060;branch=z9hG4bK2f680b 0-e89fcc28;received=10.129.47.146\r\n Call-ID: 6354@10.129.47.146\r\n From: 12345678 <sip:5088623613@10.129.47.146>;tag=794730195\r\n To: <sip:5088628562@10.129.47.165>;tag=a94c095b773be1dd6 e8d668a785a9c84359a223a\r\n Contact: <sip:5088628562@10.129.47.165:5060>\r\n CSeq: 1 INVITE\r\n Allow: OPTIONS, CANCEL, UPDATE\r\n Server: Dialogic-SIP/10.5.3.270 IMG_F 22\r\n Content-Type: application/sdp\r\n Content-Length: 178\r\n \r\n v=0\r\n o=Dialogic_SDP 1 0 IN IP4 10.129.47.165\r\n s=Dialogic-SIP\r\n c=IN IP4 10.129.47.166\r\n t=0 0\r\n m=audio 8004 RTP/AVP 0\r\n a=rtpmap:0 PCMU/8000\r\n a=silenceSupp:off - - - -\r\n a=ptime:20\r\n 06:01:04.289 CALL(SIP) (22:00002:00) RCVD Cut Thru from VPPL 06:01:04.289 CALL(SIP) (22:00002:00) RCVD Connect from VPPL 06:01:06.259 CALL(ISD) (22:00002:01) RCVD Connect from Network 06:01:06.259 CALL(ISD) (22:00002:01) SENT Connect Ack to Network 06:01:06.259 CALL(ISD) (22:00002:01) SENT Connect to L4 06:01:06.259 CALL(L4) (22:00002:01) RCVD Connect from ISDN 06:01:06.259 CALL(L4) (22:00002:01) SENT CPE of ANSWER to GCL 06:01:06.259 CALL(GCL) (22:00002:01) RCVD CPE of ANSWER from L4 06:01:06.259 CALL(GCL) (22:00002:01) SENT Call Answered to GCL 06:01:06.259 CALL(GCL) (22:00002:00) SENT CPE of ANSWER to L4 06:01:06.259 CALL(L4) (22:00002:00) RCVD CPE of ANSWER from GCL 06:01:06.259 CALL(L4) (22:00002:00) SENT Connect to SIP 06:01:06.259 CALL(SIP) (22:00002:00) RCVD Connect from L4 06:01:06.259 CALL(SIP) (22:00002:00) Session Refresh is not Needed 06:01:06.259 CALL(SIP) (22:00002:00) SENT 200 OK INVITE W/SDP to 10.129.47.146:5060 UDP 06:01:06.259 CALL(SIP) (22:00002:00) <--- [10.129.47.146, 5060 <- 10.129.47.165, 5060] SIP/2.0 200 OK\r\n Via: SIP/2.0/UDP 10.129.47.146:5060;branch=z9hG4bK2f680b 0-e89fcc28;received=10.129.47.146\r\n Call-ID: 6354@10.129.47.146\r\n From: 12345678 <sip:5088623613@10.129.47.146>;tag=794730195\r\n To: <sip:5088628562@10.129.47.165>;tag=a94c095b773be1dd6 e8d668a785a9c84359a223a\r\n Contact: <sip:5088628562@10.129.47.165:5060>\r\n CSeq: 1 INVITE\r\n Server: Dialogic-SIP/10.5.3.270 IMG_F 22\r\n Allow: INVITE, BYE, REGISTER, ACK, OPTIONS, CANCEL, SUBS CRIBE, NOTIFY, INFO, REFER, UPDATE\r\n Supported: path, replaces, timer, tdialog\r\n Accept: application/sdp, application/dtmf-relay, text/pl ain\r\n Content-Type: application/sdp\r\n Content-Length: 178\r\n \r\n v=0\r\n o=Dialogic_SDP 1 0 IN IP4 10.129.47.165\r\n s=Dialogic-SIP\r\n c=IN IP4 10.129.47.166\r\n t=0 0\r\n m=audio 8004 RTP/AVP 0\r\n a=rtpmap:0 PCMU/8000\r\n a=silenceSupp:off - - - -\r\n a=ptime:20\r\n

Configuration

Below are instructions on how to configure the IMG 2020 to MAP the Call Proceeding message to a SIP 183 message. Before configuring, the IMG 2020 must have an initial configuration created on it. Refer to the Basic Configurations procedure and verify the basic functionality has been configured. The procedure below describes how to configure the IMG 2020 for the feature above. In the procedure, the incoming side is SIP and the outgoing side will be ISDN. 

Procedure

Create ISDN Signaling, ISDN Channel Group, and ISDN B-Channels/Circuits

  • Right click on the Signaling object and select New ISDN. A ISDN D-Channels object will get created. This is a container object and no configuration is needed here. Refer to the ISDN - Signaling topic for more information on this object.

  • Right click on the ISDN D-Channels object and select New ISDN D Channel. Configure the D-Channel in this object. Refer to the ISDN D-Channel topic for more information on configuring this object.

  • Right click on IMG EMS and select New Routing Configuration. This is a container object and no configuration is needed here. A Routing Configuration Pane will appear. Refer to the Routing Configuration topic for more information on this object.

  • Right click on Routing Configuration and select New Channel Groups. A Channel groups container object is created. This object will allow multiple channel groups to be created beneath it. Refer to the Channel Groups topic for more information on this object.

  • Right click on the Channel Groups Object and select New Channel Group. A Channel Group Object will appear. Enter a name for this channel group and set the Signaling Type to ISDN. In this example, the channel group was labeled ChGrp_ISDN. Refer to the Channel Group topic for more information on configuring this object.

  • Right click on the ISDN Channel group just created and select New ISDN Group. Select a D-Channel from drop down menu in the ISDN D channel field.

  • To enable the Interworking of the Call Proceeding message, the Call Proceeding IW Procedure field must be set to Enabled. Select Enabled from drop down menu in this field. See screen capture below.

PKN: Need Web GUI screenshot to replace ClientView GUI.

Refer to the ISDN Group topic for more information on configuring this object.

  • Right click on the ISDN Group object just created and select New ISDN Circuits. Select which DS-1s/DS-0s will be utilized in this ISDN circuits group. Refer to the IMG 1010 - ISDN Circuits topic for more information on configuring this object.

Create SIP SGP and SIP_ISDN Interworking objects

Configure the SIP SGP and then the SIP_ISDN Interworking object. Within the SIP_ISDN Interworking object the Interworking of the CALL PROCEEDING message can be configured.

  • Right click on the Profiles object and select New SIP SGP. Once SIP SGP pane is created, change the SIP Profile Id field to something other than 0 by selecting a different ID from the drop down menu. This will allow user to edit the SIP Profile (SGP) object.

  • Enter a name in the SIP Profile Name field that identifies the SIP Profile (SGP) being created. In this procedure, the SIP Profile (SGP) object was labeled Call_Proceeding_Profile. Refer to SIP Profile - SGP topic for more information on configuring this object.

  • Right click on the SIP SGP Profile object and select New SIP_ISDN Interworking. In the SIP_ISDN Interworking object that appears select Enabled from the drop down menu in the Call Proceeding IW Procedure field. See screen capture below.

PKN: Need Web GUI screenshot to replace ClientView GUI.

Refer to the SIP_ISDN Interworking topic for more information. 

Create SIP Signaling

Configure the SIP signaling stack on the IMG 2020.

Right click on the Signaling object and select New SIP. A SIP Signaling object will appear. Configure the SIP Signaling object. Refer to the SIP Signaling - SIP topic for information on configuring this object.

Create SIP Gateway

Create an External Network Element and configure an external gateway under it. This gateway will be the gateway that the IMG 2020 will communicate with for the ISDN_SIP Interworking feature.

  • Right click on IMG EMS and select New External Network Elements. No configuration is needed here. The External Network Element pane is a container object to multiple external entities in the network. Refer to External Network Elements topic for more information.

  • Right click on the External Network Elements object and select New External Gateways. Again, no configuration is accomplished here. Refer to External Gateways object for more information.

  • Right click on External Gateways object and select New External Gateway. Enter a name to identify this gateway, modify the Gateway Signaling Protocol field to display SIP. In this procedure the External Gateway was labeled ISDN_SIP_IW_GW.

  • Enter the IP address of the Gateway in the Gateway IP Address field. In the SIP Profile field, select from drop down menu the SIP Profile (SGP) create earlier for this feature. Refer to screen capture below.

PKN: Need Web GUI screenshot to replace ClientView GUI.

Refer to the External Gateway topic for more information. 

Create SIP Channel Group

  • Right click on Channel Groups object created earlier and select New Channel Group. Set the Signaling Type field to SIP and enter a name for this channel group. In this procedure the SIP Channel Group was labeled ISDN_SIP_IW_ChGrp. Refer to the Channel Group topic for more information on configuring a SIP Channel Group.

  • Right Click on the SIP channel group created and select New IP Network Element. Select from the drop down menu in the IP Network Element field the External SIP Gateway configured for this feature. See screen capture below.

PKN: Need Web GUI screenshot to replace ClientView GUI.

Configuration Tree

Below is screen capture of the tree in Web GUI after the procedure above has been achieved.

PKN: Need Web GUI screenshot to replace ClientView GUI. 

Configure Routing between the SIP Channel group and the ISDN Channel group

At this point the feature has been configured and both the ISDN and SIP channel groups have been configured. Using routing information, configure the routing so the ISDN channel group and SIP channel group created route to each other.

Additional Information

  • By default, the ISDN Call Proceeding to SIP 183 Interworking feature is set to disabled, the IMG 2020 will not send any message to the SIP side upon on receipt of ISDN Call Proceeding message, the behavior will stay the same as it is today.

  • If the ISDN Call Proceeding Interworking to SIP 183 feature was set to enabled and a Progress Indicator of No. 1 or No. 8 is not present or the Progress Indicator is something other than No. 1 or No. 8, the IMG 2020 will not send any message to SIP side and the behavior will stay the same as it is today.

  • If the ISDN Call Proceeding Interworking to SIP 183 feature was set to enabled and the IMG 2020 receives an ISDN ALERTING message after the CALL PROCEEDING message, the mapping will be as follows:

 

If the ISDN CALL PROCEEDING message contains progress indicator No.1 or No.8, the CALL PROCEEDING message will be mapped to the SIP 183 PROGRESS message and the voice path established. ISDN ALERTING will NOT be mapped to any SIP messages.

If the ISDN CALL PROCEEDING does NOT contain progress indicator No.1 or No.8, the CALL PROCEEDING will NOT be mapped to any SIP 183 PROGRESS message and ISDN ALERTING will be mapped to SIP 180 RINGING and the voice path established.

 

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