QoS Settings 1

[AlexLD]

So right now we have told our MPLS provider to give the highest priority to RTP traffic from our IP Office system to our 7 other IP office systems in our MPLS (and vice versa). Thre is obviously something wrong with the setting because when we question the performance we were told the following:

Hello, in regards to tickets 7636198 and 7636228. We are seeing pattern of high utilization everyday on the BURLINGAME multilink. Also, both reported multilinks have BE drops - as ICMP typically falls into BE, this would account for high latency. Finally, neither multilink has any AF traffic. All told, customer should rethink the QoS settings at each site, or increase bandwidth at BURLINGAME. Please see attached graphs for details. Holding ticket 24 hours. Thank you.



What QoS settings should we be using on the MPLS? Anyone know what my response should be? This is just above my head and any help would be appreciated.

 

[CarGoSki]

Need EF for voip.

I think that AF is used for video over ip.

 

[AlexLD]

Can anyone confirm that the VOIP between the IP Office systems in an SCN is RTP traffic in the range of 49152 - 53246? From what we can see it seems that IP Office uses H.425 to setup the call and then hands it off to an un-encapsulated RTP stream in that port range. Does that sound right to anyone?

 

[hairlessupportmonkey]

You can check the RTP ports used in Manager
RTP Port Number Range: Software level = 3.0+.
For each VoIP call, a receive port for incoming Real Time Protocol (RTP) traffic is selected from a defined range of possible ports, using the even numbers in that range. The Real Time Control Protocol (RTCP) traffic for the same call uses the RTP port number plus 1, that is the odd numbers. For control units and Avaya H.323 IP phones, the default port range used is 49152 to 53246. On some installations, it may be a requirement to change or restrict the port range used. It is recommended that only port numbers between 49152 and 65535 are used, that being the range defined by the Internet Assigned Numbers Authority (IANA) for dynamic usage.

· Port Range (minimum): Default = 49152. Range = 1024 to 64510.
This sets the lower limit for the RTP port numbers used by the system.

· Port Range (maximum): Default = 53246. Range = 2048 to 65534.
This sets the upper limit for the RTP port numbers used by the system. The gap between the minimum and the maximum must be at least 1024.

You can then see the data in SSA when you enable RTCP monitoring:

Enable RTCP Monitor On Port 5005: Default = On. Software level = 5.0+.
For 1600, 4600, 5600 and 9600 Series H323 phones, the system can collect VoIP QoS (Quality of Service) data from the phones. For other phones, including non-IP phones, it can collect QoS data for calls if they use a VCM channel. The QoS data collected by the system is displayed by the System Status Application.

· This setting is mergeable. However it only affects H323 phones when the register with the system. therefore any change to this setting requires H323 phones that have already been registered to be rebooted. Avaya H323 phones can be remotely rebooted using the System Status Application.

· The QoS data collected includes: RTP IP Address, Codec, Connection Type, Round Trip Delay, Receive Jitter, Receive Packet Loss.

· This setting is not the same as the RTCPMON option within Avaya H323 phone settings. The system does not support the RTCPMON option



ACSS - SME
General Geek

 

[hairlessupportmonkey]

P.S - thats just a copy and paste from the Manager Help file.

ACSS - SME
General Geek

 

[hairlessupportmonkey]

Also in Monitor / Status / RTP Streams might also tell you some useful information.

ACSS - SME
General Geek

 

[mattKnight]

Use wireshark on a the mirrored port that hands of to the router. This will show you what is currently marked on the packets.

Depending on the handsets, you may find that certain calls are marked correctly and others are not.

Try making a SCN call from an analogue handset and see what the sending stream is marked at.

You may also need to check that DSCP trust is enabled on your switches - under certain conditions, switches will strip DSCP markings

Take Care

Matt
I have always wished that my computer would be as easy to use as my telephone.
My wish has come true. I no longer know how to use my telephone.

 

[AlexLD]

We've confirmed the DSCP tags are still there, and our carrier can see them, but the issues persist. They insist they are honouring the QoS but it doesn't look that way to me.