Options
QoS LLQ
azaghul
Member Posts: 569 ■■■■□□□□□□
Just revising CVOICE v8 and looking at QOS. The cisco model recommends 33% for RTP media, 5% for RTP signalling and then all the rest.
From my limited reading so far, would this be a valid config? (my router takes the config, but that does'nt mean it will work). Voice and video sharing the same PQ, but treated differently based on their DSCP value for "dropping".
From my limited reading so far, would this be a valid config? (my router takes the config, but that does'nt mean it will work). Voice and video sharing the same PQ, but treated differently based on their DSCP value for "dropping".
class-map match-any RTP-VOICE match protocol rtp audio class-map match-any RTP-VIDEO match protocol rtp video class-map match-any RTP-SIGNALLING match protocol sip match protocol h323 match protocol skinny match protocol mgcp policy-map QOS-POLICY class RTP-VOICE set dscp ef priority percent 33 class RTP-VIDEO set dscp af41 priority percent 33 class RTP-SIGNALLING set dscp cs3 bandwidth percent 5 class class-default fair-queue random-detect
Comments
-
Options
networker050184
Mod Posts: 11,962 Mod
This is a valid configuration. Neither traffic will be dropped by this current router on this interface (unless of course it's exceeding the alloted bandiwdth and then only in times of congestion) due to DSCP value because the priority queue will always be emptied first. If the interface is overrun thats a different story as there is a finite ammount of packet buffer space available.An expert is a man who has made all the mistakes which can be made. -
Optionsazaghul
Member Posts: 569 ■■■■□□□□□□
So just to confirm what I think you're saying...
Both voice and video are sharing the same 33% bandwidth in the PQ.
If the PQ is experiencing congestion, then the DSCP values come into play and video is dropped first. -
Optionsnetworker050184
Mod Posts: 11,962 Mod
No, the PQ now has 66% of bandwidth. The DSCP values will never come into play for this traffic on this interface. The PQ is FIFO and does not perform any kind of early drop. Just plain old tail drop.An expert is a man who has made all the mistakes which can be made.
-
Optionsazaghul
Member Posts: 569 ■■■■□□□□□□
OK, thanks for clearing that up....my misunderstanding of the QoS "lite" material in CVOICE. As always, more reading to do...
Do you know of any study material that takes a middle ground for QoS between CVOICE and the full QOS course? -
Options
pitviper
Member Posts: 1,376 ■■■■■■■□□□
Check out the Enterprise QOS SRND guide on Cisco.com. It's a little dated but still relavent and easy enough to follow (wish that could be said for some of their other documentation).CCNP:Collaboration, CCNP:R&S, CCNA:S, CCNA:V, CCNA, CCENT -
Optionsazaghul
Member Posts: 569 ■■■■□□□□□□
Thanks for that pitviper, another book to add to the reading list.
I've had a quick look at the SRND, seems my config was in the right direction as networker said, just a deeper understanding required.
