Mitel 3300 LAN Policy (QoS) question

[msouva]

Hello,

     I have a Mitel 3300 here that has VoIP phone users reporting robotic calls.  We believe this to be a possible issue with the LAN Policy settings.  It is currently set as follows:

                                     DSCP [0-63]      L2 Priority [0-7]   
                Voice Media      44                        6         
                Voice Signalling   44                        6         
                Standard                0                        0

     I have checked the phones and can see that the DSCP is set for 46 and the L2 Priority is set for 5.

     My question is that should the above settings on the 3300 be changed to reflect what is on the phones?  I have a wireshark trace file that shows the phone has the 46 for the DSCP, but the 3300 has a 0. 

     Is my logic correct and that these setting should match and the LAN Policy screen controls what the 3300 is set for on the DSCP?

     Here are a couple of packets from the wireshark:

                        Internet Protocol Version 4, Src: 10.100.1.1xx, Dst: 10.100.1.2xx
                          0100 .... = Version: 4
                            .... 0101 = Header Length: 20 bytes
                         Differentiated Services Field: 0xb8 (DSCP: EF PHB, ECN: Not-ECT)
                        1011 10.. = Differentiated Services Codepoint: Expedited Forwarding (46)
                             .... ..00 = Explicit Congestion Notification: Not ECN-Capable Transport (0)
                          Total Length: 200

                          Internet Protocol Version 4, Src: 10.100.1.2xx, Dst: 10.100.1.1xx
                          0100 .... = Version: 4
                            .... 0101 = Header Length: 20 bytes
                            Differentiated Services Field: 0x00 (DSCP: CS0, ECN: Not-ECT)
                              0000 00.. = Differentiated Services Codepoint: Default (0)
                              .... ..00 = Explicit Congestion Notification: Not ECN-Capable Transport (0)

                              Total Length: 200


Thank you,

Mark

[johnp]

Enter the Differentiated Services Code Point Value (0-63) for real-time voice streaming (e.g., phone conversations) and signaling information that requires low network latency (e.g., MiNET Mitel's proprietary signaling protocol used to control Mitel IP and TDM telephones., SIP, SAC Switch Application Communications (SAC) protocol. A messaging protocol used by IP phones to support graphics-based software applications on the MiVoice Business system. List of SAC sets as of MCD 6.0: 5230, 5235, 5240, 5304, 5312, 5320, 5320e, 5324, 5330, 5330e, 5340, 5340e, 5360, 5560 IPT, Navigator, WebSet (5140 or 5240). (Note: 5230, 5240, and WebSet are no longer supported.)). This value should match the value programmed for DHCP Option 43 and 125. The defaults are 46 for voice media and 24 for voice signaling. The DSCP value for non-voice media or signaling traffic (represented by the 'Standard' field) is fixed at 0 (zero). Data transfers (e.g., TCP/IP packets) that are not time sensitive fall into the Standard service class.

This is from the current help file. Signalling used to be 26, L2P has gone from 6 to 5. all seem to be the same as Cisco defaults

[msouva]

Thank you for the information johnp.  The question I have was for the LAN Policy settings should these be set to what I am seeing in the Wireshark trace?  The two examples I had, the one with the Differentiated Services Codepoint: Default (0) is from the 3300 and the one with Differentiated Services Codepoint: Expedited Forwarding (46) is from the 5330e IP phone. 

I looked at the DHCP settings for the 3300 and it is showing that the phones should be getting a dscp of 44, but from the trace this does not seem to be the case.  I would like to change the LAN Policy on the 3300 to match the trace and see if the switch changes from Default (0) to (46).

Thank you,

Mark

[sarond]

The policy that the phones get will be in the DHCP Scope.
The LAN policy on the form you are looking at is for the controller itself.

[VinceWhirlwind]

Signaling doesn't matter so much - it's TCP and latency isn't very important.
The most important QoS is for the actual voice traffic. For internal calls, this is set by the phone on each voice packet it sends, and should be set as DSCP46. L2P should be set to match whatever the network uses - Mitel like to use 6, but a Cisco network will by default be setup for voice to use 5, whereas an HP network uses 6. This is set in the DHCP option.
The controller will have to be setting QoS for packets coming from the far end of an external call coming in off the PSTN. You set this on your LAN policy form. Set it the same as the QoS is set for the handsets.
Bear in mind some networks might ignore what the handsets and controller are setting and might have policies to re-mark all traffic.
 
It might be useful to find out what kind of calls were affected - Internal, or External, or both?