SIP in higher education

[Nimal Ratnayake <>]

Hi Steve,

It looks like in my case the problem is in the POTS call leg.  As soon 
as the REFER
is received the gateway sends an ISDN message to the PBX which drops the 
call.
I have attached the relevant excerpt from the router debug log.

Thanks.

Nimal R.

Steve Blair wrote:

> Hello Nimal:
>
>   I'm out of the office for out holiday however when I return on Monday I
> will look into this a bit. I think I am having a similar problem. For 
> me a
> call comes in from the PSTN via the Cisco gateway to an IP phone. The
> IP phone blind transfers the call to another IP device and the call 
> drops.
> I'll let you know if I discover anything of interest. May I ask that you
> do the same?
>
> Thanks,Steve
>
> Nimal Ratnayake wrote:
>
> > Apologies for duplicates. previously posted on 
> > .
> >
> > ---------
> >
> > Hi,
> >
> > When a call between a SIP phone and a PBX extension is transfered
> > by the SIP phone to another SIP phone, the SIP gateway does not
> > seem to handle the REFER correctly.  I am using a Cisco 3640 router
> > running IOS 12.3(12).  The call flow is as shown below ( I have
> > omitted the proxy in this picture)
> >
> >
> > SIP                             PBX-GW
> > IP=A.B.C.D                      IP=P.Q.R.S
> > 1602                            3423
> >
> > -------------INVITE--------------->
> > <------------TRYING----------------
> > <------SESSION PROGRESS------------
> > <--------------OK------------------
> > --------------ACK----------------->
> > ----INVITE c=IN IP4 0.0.0.0------->
> > <-----OK c=IN IP4 P.Q.R.S----------
> > --------------ACK----------------->
> > -------REFER Refer-To: 1600------->
> > <-----------Accepted---------------
> > <------------NOTIFY OK-------------
> > -------------- OK----------------->
> >
> >
> > Shouldn't the gateway do an invite to 1600 after receiving REFER
> > *before* sending NOTIFY?
> >
> > Any help or pointers to solve the problem would be appreciated.
> >
> > Thanks.
> >
> > Nimal Ratnayake

Nov 26 11:06:14 pdn4 35298: Nov 26 05:06:04.622: Received: 
Nov 26 11:06:14 pdn4 35299: REFER sip: SIP/2.0
Nov 26 11:06:14 pdn4 35300: Max-Forwards: 10
Nov 26 11:06:14 pdn4 35301: Record-Route: <sip:192.248.40.8;ftag=2825252803;lr=on>
Nov 26 11:06:14 pdn4 35302: Via: SIP/2.0/UDP 192.248.40.8;branch=z9hG4bK0dad.ccf009c7.0
Nov 26 11:06:14 pdn4 35303: Via: SIP/2.0/UDP 10.40.15.19:5060;branch=z9hG4bKcbf88d0dc248a5e8
Nov 26 11:06:14 pdn4 35304: From: sip:;tag=2825252803
Nov 26 11:06:14 pdn4 35305: To: sip:;tag=525971C8-1684
Nov 26 11:06:14 pdn4 35306: Call-ID: 
Nov 26 11:06:14 pdn4 35307: CSeq: 2 REFER
Nov 26 11:06:14 pdn4 35308: Contact: Nimal Ratnayake <sip::5060;user=phone;transport=udp>
Nov 26 11:06:14 pdn4 35309: User-Agent: Cisco-CP7905/1.3.
Nov 26 11:06:14 pdn4 35310: 1-050608A
Nov 26 11:06:14 pdn4 35311: Allow: ACK, BYE, CANCEL, INVITE, NOTIFY, OPTIONS, REFER, REGISTER, PRACK, UPDATE
Nov 26 11:06:14 pdn4 35312: Supported: replaces, 100rel
Nov 26 11:06:14 pdn4 35313: Refer-To: sip:
Nov 26 11:06:14 pdn4 35314: Referred-By: sip::5060
Nov 26 11:06:14 pdn4 35315: Content-Length: 0
Nov 26 11:06:14 pdn4 35316: 
Nov 26 11:06:14 pdn4 35317: 
Nov 26 11:06:14 pdn4 35318: Nov 26 05:06:04.622: HandleUdpSocketReads :Msg enqueued for SPI with IPaddr: 192.248.40.8:5060
Nov 26 11:06:14 pdn4 35319: Nov 26 05:06:04.626: ****Found CCB in UAC table
Nov 26 11:06:14 pdn4 35320: 
Nov 26 11:06:14 pdn4 35321: Nov 26 05:06:04.626: CCSIP-SPI-CONTROL:  act_active_new_message
Nov 26 11:06:14 pdn4 35322: Nov 26 05:06:04.626: CCSIP-SPI-CONTROL:  sact_active_new_message_request
Nov 26 11:06:14 pdn4 35323: Nov 26 05:06:04.626: CCSIP-SPI-CONTROL:  Converting TimeZone LKT to SIP default timezone = GMT
Nov 26 11:06:14 pdn4 35324: Nov 26 05:06:04.626: sip_stats_method
Nov 26 11:06:14 pdn4 35325: Nov 26 05:06:04.626: CCSIP-SPI-CONTROL:  sipSPIReferIsValid 
Nov 26 11:06:14 pdn4 35326: Nov 26 05:06:04.626: transfer digits: 1603
Nov 26 11:06:14 pdn4 35327: 
Nov 26 11:06:14 pdn4 35328: Nov 26 05:06:04.630: CCSIP-SPI-CONTROL:  sipInitCallTransfer 
Nov 26 11:06:14 pdn4 35329: Nov 26 05:06:04.630:  Queued event from SIP SPI : SIPSPI_EV_SEND_MESSAGE
Nov 26 11:06:14 pdn4 35330: Nov 26 05:06:04.630: sip_stats_status_code
Nov 26 11:06:14 pdn4 35331: Nov 26 05:06:04.630: 0x6398E050 : State change from (STATE_ACTIVE, SUBSTATE_NONE)  to (STATE_RECD_XFER, SUBSTATE_NONE)
Nov 26 11:06:14 pdn4 35332: Nov 26 05:06:04.634: ISDN Se3/0:15 Q931: TX -> FACILITY pd = 8  callref = 0x8C47 
Nov 26 11:06:14 pdn4 35333: 	Calling Party Number i = 0x80, '3423' 
Nov 26 11:06:14 pdn4 35334: 		Plan:Unknown, Type:Unknown 
Nov 26 11:06:14 pdn4 35335: 	Called Party Number i = 0x80, '1602' 
Nov 26 11:06:14 pdn4 35336: 		Plan:Unknown, Type:Unknown
Nov 26 11:06:15 pdn4 35337: Nov 26 05:06:04.638: Sent: 
Nov 26 11:06:15 pdn4 35338: SIP/2.0 202 Accepted
Nov 26 11:06:15 pdn4 35339: Via: SIP/2.0/UDP 192.248.40.8;branch=z9hG4bK0dad.ccf009c7.0,SIP/2.0/UDP 10.40.15.19:5060;branch=z9hG4bKcbf88d0dc248a5e8
Nov 26 11:06:15 pdn4 35340: From: <sip:>;tag=2825252803
Nov 26 11:06:15 pdn4 35341: To: <sip:>;tag=525971C8-1684
Nov 26 11:06:15 pdn4 35342: Date: Sat, 26 Nov 2005 05:06:04 GMT
Nov 26 11:06:15 pdn4 35343: Call-ID: 
Nov 26 11:06:15 pdn4 35344: Server: Cisco-SIPGateway/IOS-12.x
Nov 26 11:06:15 pdn4 35345: CSeq: 2 REFER
Nov 26 11:06:15 pdn4 35346: Content-Length: 0
Nov 26 11:06:15 pdn4 35347: 
Nov 26 11:06:15 pdn4 35348: 
Nov 26 11:06:15 pdn4 35349: 
Nov 26 11:06:15 pdn4 35350: Nov 26 05:06:04.666: ISDN Se3/0:15 Q931: RX <- STATUS pd = 8  callref = 0x0C47 
Nov 26 11:06:15 pdn4 35351: 	Cause i = 0x81E36C70 - Information element not implemented 
Nov 26 11:06:15 pdn4 35352: 	Call State i = 0x0A
Nov 26 11:06:26 pdn4 35353: Nov 26 05:06:17.038: ISDN Se3/0:15 Q931: RX <- DISCONNECT pd = 8  callref = 0x0C47 
Nov 26 11:06:26 pdn4 35354: 	Cause i = 0x8190 - Normal call clearing 
Nov 26 11:06:26 pdn4 35355: 	User-User i = 0x00FE
Nov 26 11:06:26 pdn4 35356: Nov 26 05:06:17: %ISDN-6-DISCONNECT: Interface Serial3/0:0  disconnected from 3423 , call lasted 39 seconds