Saturday, March 19, 2011

Outbound calls to gateway through Lync Server 2010 front-end fails with server trace error: “SIP/2.0 488 Not Acceptable Here” error.

Problem

While setting a new new gateway for a client to pilot an upstream topology, I ran into a problem during the initial setup where all of test calls we send out to the gateway fails with the trace error: SIP/2.0 488 Not Acceptable Here as shown in the following snooper screenshot:

image

The following is the copied and pasted output from the snooper logs:

TL_INFO(TF_PROTOCOL) [2]3E40.3564::03/15/2011-19:01:21.136.0013aac7 (S4,SipMessage.DataLoggingHelper:sipmessage.cs(686))[613569537]
<<<<<<<<<<<<Incoming SipMessage c=[<SipTcpConnection_3BDE12>], 132.216.72.45:57742<-132.216.72.46:5066
SIP/2.0 488 Not Acceptable Here
FROM: <sip:lyncfe01.domain.ca:5068;transport=Tcp;ms-opaque=7df192af9cba01ee>;epid=5F6A59558E;tag=b6e48e8ce8
TO: <sip:NET-SBC1.domain.ca>
CSEQ: 8 OPTIONS
CALL-ID: 51dc9494cae1471a9abbf42395940fa3
VIA: SIP/2.0/TCP 132.216.72.45:57742;branch=z9hG4bKbb80c177
CONTENT-LENGTH: 0
USER-AGENT: NET UX 1.0v221 SW/WinVer
------------EndOfIncoming SipMessage

Solutions

What ended up being the problem was that we initially wanted to use TLS but because we had problems importing the certificate for the gateway, we ended up configuring the connection between the Mediation server (collocated with the front-end server) and the gateway (NET UX2000) as TCP with no encryption.  What we forgot to do was to change the media list of the gateway to not use Crypto as shown in the following lists and screenshots:

Media List:

  • Default Media List
  • OCS to PSTN: UC Media List w/Crypto
  • Lync PSTN: UC Media List w/Crypto

image

Media List:

  • Default Media List
  • OCS to PSTN: UC Media List w/Crypto
  • Lync PSTN: UC Media List w/Crypto

image

As soon as we changed all of the media lists to Default Media List in the gateway configuration, the calls outbound to the PSTN network started to work.  As this can probably happen to any gateway vendor, if you encounter the error SIP/2.0 488 Not Acceptable Here in your front-end traces, have a look at the media list for the signally groups and call routing tables of your gateway.

8 comments:

Anonymous said...

Terence, thanks for such a good post. I have similar problem. I have a collocated FE/Mediation server. This server has got two Ethernet cards. The first connects to iscsi boot. And the second connects to my LAN. I have enable TCP on the mediation side and add a gateway to listen on TCP port 5060. I have done all I can but outbound call does not work. When I do an out bound test call, I get this error message:
10061, No connection could be made because the target machine actively refused it 10.10.10.10:5061

I have read on the internet and tried all what others suggested, but to no avail. I will be so glad if you can help me and point me to the right direction.

Terence Luk said...

Hi,

What I've found useful for further troubleshooting is to use Network Monitor or Wireshark to try and capture more information. Have you tried using those tools to do packet captures for more analysis?

MS Idris said...

Great post. I still haven't come across anyone with the problem we are facing.

Environment is Merged Topology (OCS R2 Edge server handles all external connectivity). All calls (PC-to-CX600 phones, PSTN)fails at first attempt and connects when redialled.

MS Idris said...

Great Post. We are facing a peculiar issue. All calls initiated from PC to Lync phones (CX600)fail at first attempt and connects once redialled.

Any tips

Terence Luk said...

Hi Idris,

I remember coming across a similar problem in the past with OCS 2007 R1 or R2 but I can't remember how I fixed it. Your best bet at this point is to use Snooper to do a trace and review the call setup and tear down to see if it sheds anymore insight as to why this is happening.

MS Idris said...

Thanks Terence.

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