HDX and QoS

[Anonymous]

Hi Guys,

we have recently implemented QoS on our link between company sites, specifically DSCP 46 (expedite forwarding) for premium traffic.

Now  we plan to apply this kind of QoS on  HDX system, but i'm not sure  about correct DiffServ values for audio video and control.

On admin guide it says  range can be between 0 and 63 but would be nice to have a "best practice" configuration.

Do you have any advice?

Thanks

[Anonymous]

 DSCP 46 equates to

TOS       0xBE

Precedence Bits      10111000

Normally we recommend AF41 which is the default for Polycom end points and the RMX bridge.

[Anonymous]

IMHO, in the IP Precedence world you have a range from 0-7 & Polycom defaults to

Video 4

Audio 5

Control 3

I understand, generally 6 & 7 are "reserved" for network integrity signaling (router tables et al).

So in the DiffServer world where you have 0-63 the IP Precedence model would suggest

Video 36

Audio 45-46

Control 27-29

Ofcourse, all your network gear would have to understand this too & if you're connecting over the internet QoS just won't work but Polycom LPR will do it's best to compensate.

Recommended bed time reading for QoS Insomniacs. http://www.cisco.com/en/US/tech/tk543/tk757/technologies_tech_note09186a0080094968.shtml

Regards

Pete:)

[Anonymous]

Thanks guys,

DSCP 46 has been applied on Colt link between HQ and branch office (internet calls take another way), mainly cause we have 2 ATX rooms for demo,and we always want the best video quality.

I'll try suggested settings and i'll let you know:

Video 36

Audio 45-46

Control 27-29

Cheers

[Anonymous]

Ok guys,

this is the result:

using:

Video 36

Audio 45-46

Control 27-29

there was no real benefit ,cause most of the traffic was falling outside DSCP 46.

USing the same value (46) for all, returned the best quality on our ATX (all packets fall into EF).

Cheers

[Anonymous]

A couple of questions.  I believe that we are also using this same diffserv value (46) for all of our traffic and the AF41 queue.

How is the content traffic prioritized on the network?  It appears this is competing with our Video and Audio causing quality issues.

Has anyone had experience with protecting both Lync Conferencing and Polycom Video in the same queue (AF41)?  I am thinking that the Lync traffic is also conflicting with our Polycom Video traffic and am considering using the EF queue for Polycom instead?

Any input is appreciated.

Thanks,

OldSchoolGuy