TOS/DSCP marking of SIP/RTP by 3CX Phone System

[suse]

Hello,

Your product looks and works great (extremely simple to set-up compared to other similar solutions), however one thing looks odd to me - why there's no option present to set TOS/DSCP marking of the SIP/CALL ?
I've captured the call with ethereal and SIP/RTP packets are not marked in any way (TOS not set and DSCP value 0x00).
This might present a problem if IP calls are made in distributed LAN , as in VPLS service.
Many hardware VOIP gateways provide an option to mark the originating traffic and thus make it easier for the access-level equipment to classify the VOIP sessions.

 

[[email protected]]

Is this option still available in the 7.1 phone system series?

 

[SY]

Is this option still available in the 7.1 phone system series?

Welcome to the 3CX "sand-box" (please don't take offence, it was a joke )
We didn't throw away any of useful things. MSRTPTOS parameter is exact this option. You can add it (or modify) on the "custom parameters" page. You don't need to restart anything, it must work "on fly". If it will not work as described then, please, report the issue either here (not recommended ) or send description to us (recommended )

Thanks

 

[comresource]

I have been playing with the TOS/DSCP settings and I just cannot seem to get it working. I show the TOS/DSCP settings correctly from my snom 300 but not from 3cx (I am just dialing voicemail to generate RTP traffic). Any tips from those who have this working?

 

[comresource]

Ok I found the problem. By default Windows XP disables QOS. To allow applications to mark packets properly you need to create the following registry entry.

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters

Add a DWORD DisableUserTOSSetting with value of 0

After making this change 3CX now properly tags packets.

Here is a link with more information.

http://technet.microsoft.com/en-us/magazine/2007.02.cableguy.aspx

EDIT: This is only for RTP traffic. It would be nice to also see taggin on SIP packets at some time in the future.

 

[SY]

Ok I found the problem. By default Windows XP disables QOS. To allow applications to mark packets properly you need to create the following registry entry.

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters

Add a DWORD DisableUserTOSSetting with value of 0

After making this change 3CX now properly tags packets.

Here is a link with more information.

http://technet.microsoft.com/en-us/magazine/2007.02.cableguy.aspx

EDIT: This is only for RTP traffic. It would be nice to also see taggin on SIP packets at some time in the future.

Thanks a lot for the valuable hint.