[sip-comm-dev] Does Sip Communicator support Symmetric NAT?

Archive
1

Hi,

And thanks for the great program just checked it out and it has shiny
future,

I just checked the SIP feature of the program and noticed that it just
can't register the UA when he is behind Symmetric NAT, So question in my mind has TURN or Tunneling or other feature that can do the job being
implemented in SIP communicator yet?

In addition just to note I tried to to do NAT Traverse using RealTunnel
NAT Traverse
but it didn't work either ( It works in X-lite , Express Talk)

Also I am a Network auditor and can test Network issues that may arise
by SIP Communicator thoroughly, Let me know if you needed a hand for it.

Regards,
Michael Lopez

2

Hello Michael,

На 18.05.10 12:36, michael lopez написа:

Hi,

And thanks for the great program just checked it out and it has shiny
future,

Thank you for your kind words :slight_smile:

I just checked the SIP feature of the program and noticed that it just
can't register the UA when he is behind Symmetric NAT

Symmetric NATs, or rather NATs with endpoint dependent mapping, are
generally a problem for media and not signalling itself. Therefore, if
you can't register then there's probably another reason. Could you
please send log files and wireshark dumps so that we could try to see
what's happening?

, So question in my
mind has TURN or Tunneling or other feature that can do the job being
implemented in SIP communicator yet?

Currently SIP Communicator relies on the servers to handle NAT
traversal. Most of the popular deployments and server implementations
would overwrite your SDP and then relay media.

We are currently working on an ICE implementation within the ice4j [1]
project. TURN is one of the features that will be implemented in ice4j
but that's probably not going to affect you since there are currently
very few SIP providers that are maintaining TURN server deployments.

In addition just to note I tried to to do NAT Traverse using RealTunnel
NAT Traverse but it didn't work either ( It works in X-lite , Express Talk)

Never really tried it. Would probably need to look at dumps to see what
may be going wrong.

Cheers,
Emil

[1] http://ice4j.org

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3

Hello Emil,

Actually I was exploring other features of sip communicator and it deserves more kind words :slight_smile: , For The log files I attached them to this email so that can be analyzed to know the problem.

Also I tested other Softphones; X-lite and ExpressTalk are successful only when "RealTunnel NAT Traversal" is used as Outbound Proxy ( localhost:5061).

The only software that I found working out of the box is Emansip (from Antisip.com) with TLS as Trasport Protocol (Also tested outgoing calls, incoming calss OK), I also attached a Wireshark dump for it in case it might be handy.

Also I have 2 Windows Servers connected to Public network if there be anything necessary (proxy, tunnel, SIP proxy, RTP proxy) to be tested I can be a help.

Regards
Michael Lopez

sip-communicator0.log.txt (34.2 KB)

wireshark-capture-dump-emansip.pcap (22.7 KB)

wireshark-capture-dump-sip-communicator.pcap (23.8 KB)

···

________________________________
From: Emil Ivov <emcho@sip-communicator.org>
To: dev@sip-communicator.dev.java.net
Cc: michael lopez <egold_offers@yahoo.co.uk>
Sent: Tue, 18 May, 2010 15:53:45
Subject: Re: [sip-comm-dev] Does Sip Communicator support Symmetric NAT?

Hello Michael,

На 18.05.10 12:36, michael lopez написа:

Hi,

And thanks for the great program just checked it out and it has shiny
future,

Thank you for your kind words :slight_smile:

I just checked the SIP feature of the program and noticed that it just
can't register the UA when he is behind Symmetric NAT

Symmetric NATs, or rather NATs with endpoint dependent mapping, are
generally a problem for media and not signalling itself. Therefore, if
you can't register then there's probably another reason. Could you
please send log files and wireshark dumps so that we could try to see
what's happening?

, So question in my
mind has TURN or Tunneling or other feature that can do the job being
implemented in SIP communicator yet?

Currently SIP Communicator relies on the servers to handle NAT
traversal. Most of the popular deployments and server implementations
would overwrite your SDP and then relay media.

We are currently working on an ICE implementation within the ice4j [1]
project. TURN is one of the features that will be implemented in ice4j
but that's probably not going to affect you since there are currently
very few SIP providers that are maintaining TURN server deployments.

In addition just to note I tried to to do NAT Traverse using RealTunnel
NAT Traverse but it didn't work either ( It works in X-lite , Express Talk)

Never really tried it. Would probably need to look at dumps to see what
may be going wrong.

Cheers,
Emil

[1] http://ice4j.org

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4

На 18.05.10 15:28, michael lopez написа:

Also I tested other Softphones; X-lite and ExpressTalk are successful
only when "RealTunnel NAT Traversal" is used as Outbound Proxy (
localhost:5061).

If RealTunnel works as a SIP proxy then you'd have to explicitly
configure the outbound proxy in your corresponding SC account.

The only software that I found working out of the box is Emansip
(from Antisip.com) with TLS as Trasport Protocol

Did you try using TLS with SIP Communicator? I don't think iptel.org
have this so you'd have to try with OVH as you did when testing Emansip.

If this works then it could be that your NAT box is explicitly
configured to filter SIP.

Hope this helps,
Emil

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5

I just tested SC with RealTunnel but it doesn't work ( not sure of the
reason).

Also tested antisip account using SC using TLS protocol and it didn't
work either, any other sip provider that has TLS enabled to test?

I attached two wireshark dumps 1- when emansip connects to antisip
(successful) 2-when SC tries to connect to antisip ( failure) to compare

Also as a side note when I tried to change server port ( advanced
section) to another port other thant 5060 or 5061 it forced the settings back to 5060(1).

Regards,
Michael Lopez

wireshark-capture-dump-emansip.pcap (22.7 KB)

wireshark-capture-dump-sc-antisip.pcap (6.23 KB)

···

________________________________
From: Emil Ivov <emcho@sip-communicator.org>
To: dev@sip-communicator.dev.java.net
Cc: michael lopez <egold_offers@yahoo.co.uk>
Sent: Tue, 18 May, 2010 18:44:11
Subject: Re: [sip-comm-dev] Does Sip Communicator support Symmetric NAT?

На 18.05.10 15:28, michael lopez написа:

Also I tested other Softphones; X-lite and ExpressTalk are successful
only when "RealTunnel NAT Traversal" is used as Outbound Proxy (
localhost:5061).

If RealTunnel works as a SIP proxy then you'd have to explicitly
configure the outbound proxy in your corresponding SC account.

The only software that I found working out of the box is Emansip
(from Antisip.com) with TLS as Trasport Protocol

Did you try using TLS with SIP Communicator? I don't think iptel.org
have this so you'd have to try with OVH as you did when testing Emansip.

If this works then it could be that your NAT box is explicitly
configured to filter SIP.

Hope this helps,
Emil

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