Hi Bob, 

Thanks for the clarification.

 

First of all, I forgot to say, that when I call from home from 192.168.11.34
to the sipx AA  or VM, I can hear announcement. 

(Call-id OTE2YmExZGUyMjhkYWVlOTVjZWZlN2Y3YTk3MTFiY2E. in the file attached
to my previous mail).

That's why I think, that port forwarding on my office nat/router (30000 -
30500 from external to internal sipx ip) works ok.

And looking at the call OTE2YmExZGUyMjhkYWVlOTVjZWZlN2Y3YTk3MTFiY2E., (where
I heard the AA announcement) I see, that the same SDP substitution occurs. 

(And as far as I understand now, this is the way how
"far-end-nat-traversal-assist" works. Right?)

 

Regarding my eyebeam configuration:

"use local address" is set, but "enable ice" is turned on. 

I'll try to disable it and if problem will still persist, I'll take tcpdump
and snapshot.

Anyway I'll let you know about the result.

 

Thanks again,

Nikolay.

 

 

  _____  

From: Robert Joly [mailto:[email protected]] 
Sent: Monday, March 30, 2009 5:54 PM
To: Nikolay Kondratyev; [email protected]
Subject: RE: [sipX-dev] remote workers: problem with voice

 

Hi Nikolay,

First of all, thanks for providing that level of details.  I took a look at
your debug logs and here are my observations.

 

When you make the call from your Eyebeam outside of the VPN, the sipXproxy
detects that this Eyebeam is behind a remote NAT.  More specifically, it
sees that the configured IP address of the Eyebeam is 192.168.11.34 but it
is is behind a NAT whose public IP is 91.77.13.212.  

 

When the a call is made by Eyebeam to the Yates box, the NAT traversal
feature knows that there are at least one NAT between them, as such, thus
these endpoints cannot stream media directly to each other.  To allow media
to flow between the two endpoints, sipXecs needs to insert a media relay in
the middle of the RTP flow.  That media relay will dynamically learn the
port translations created by the NAT for the media session and will start
relaying packets to reachable IP:ports.  This is a long-winded way of saying
that, given the location of the Eyebeam, it is expected behavior that
sipXecs will go in an change the SDP.

 

Having said that, you are still faced with speech path issues.  I looked at
your sipXecs configuration and it appears to be fine however there are a
couple of things I would want you to check:

1- The SDP I'm getting from your eyebeam suggest that you have ICE enabled.
if you rely on sipXecs to handle your NAT traversal, you need to disable any
NAT-traversal-assist at the phones as those can conflict.  Please check the
Eyebeam configuration to ensure that 'Enable ICE' is turned off and that
that your address is set to 'Use local address'.

2- Have you opened the media ports used by the sipXecs NAT traversal feature
on your firewall?  More specifically, the range of ports 30000 to 30500 is
used to relay media of endpoints that cannot stream to each other directly.
In order for this to work, you need to open the 30000-30500 UDP port range
on your firewall and configure port forwarding rules to send traffic
received on those ports to sipXecs's private IP address (172.23.19.5).

 

If you have done those things and you are still faced with speech path
issues, please take a tcpdump of the call on your sipXecs box and send it to
me.  When you do, please specify the 'any' interface, using '-i any' so that
I can see the interprocess communication.  Here's the tcpdump command I
normally use:  tcpdump -n -nn -s 0 -i any w mycapture.cap

 

cheers,

bob

 

  _____  

From: [email protected]
[mailto:[email protected]] On Behalf Of Nikolay
Kondratyev
Sent: Monday, March 30, 2009 3:06 AM
To: [email protected]
Subject: [sipX-dev] remote workers: problem with voice

Hi all,

 

I found the following problem on my test sipx (015027) machine: under
certain circumstances there is no voice for remote worker.

 

Here is the detailed description of my setup:

I use YATE (http://yate.null.ro) as h323-sip gateway between my sipx and
avaya ip office (due to some problems with sip in avaya).

YATE is configured to relay media. And YATE is running on the same machine
as sipx, but uses port 5059 for sip, and ports 16384 - 18000 for rtp.

Sipx has dns name sipx3.lab.nstel.ru and ip address 172.23.19.5 (/24).

 

Network 172.23.0.0/16 is declared local (intranet) for sipx.

Intranet domains are

*.sipx3.lab.nstel.ru

*.yate.lab.nstel.ru

 

Remote workers can either use vpn connection, which does not differ much
from local users,  or use sipx nat traversal feature.

External (nat'ed into internal) ip address is 81.211.30.104 and is named
vpn.nstel.ru in the external dns.

When a user dials 9 and 7digits the call is routed to yate and then to pstn.

 

The problem is that:

 

When user 3853 (eyebeam), registered trough vpn (Contact:
<sip:[email protected]:51860;transport=TCP>), dials 96414045 the call is set
up and voice is ok. 

Call-id MTQ3ODFjZDBmNGFiOTliNWFmMDZjNTFhYjVlZTAyZTA. in the attached
merged.xml file.

 

But when the same user is registered using nat-traversal, and dialing the
same number, the call is set up, but there is no voice.

Call-id NGVlMWUzY2RkMDA1M2ViMTEzYTc0N2RjYTRhODU2MzQ. in the attached
merged.xml file.

 

My analysis of the problem is that, in the second (problematic) case,
sipxproxy substitutes media ports when forwarding Invite (frames 26 and 41
in the merged.xml) and 200 Ok (frames 44,47) messages.

Such substitution does not occur in the first case, and, I believe, should
not occur in the second case.

I think that it is the cause of my problem.

Can somebody please verify if my analysis is correct? Is it a bug, or a
configuration problem?

 

The whole snapshot is available at
ftp://sipx:[email protected]/sipx-configuration-sipx3.lab.nstel.ru.tar.gz

 

Thanks and regards,

Nikolay.

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