QoS Traffic-Type Prioritizations?

CiskHo · March 2010

Does anyone know where I can find info on which types of traffic would require higher levels of prioritization? I'm trying to determine which of these types of data would require the highest/lowest priorities:
video conferencing, video streaming, call clocking, net mgmt traffic, VOIP, etc.

I don't recall seeing anything at all about video in the Off Cert Guide for SWITCH and my google searching isn't coming up with any kind of hierarchial list of which traffic is more time sensitive.

CiskHo · March 2010

Anybody know what I am referring to? Maybe I got the phrasing messed up...

networker050184 · March 2010

Check this out. What goes into which traffic class and how you treat it will depend on the business needs in the end though.

http://www.cisco.com/en/US/technologies/tk543/tk759/technologies_white_paper0900aecd80295aa1.pdf

CiskHo · March 2010

Big thanks networker!!! Just what I was looking for! "QoS Best Practices" would have been a more appropriate name for this thread I think.

ilcram19-2 · March 2010

for voice dscp ef

CiskHo · March 2010

ilcram19-2 wrote: »

for voice dscp ef

Thanks but not what I need. Looking for more info in regard to which type of traffic should have higher priority. EX: Which should traffic is more time sensitive between video conferencing, VOIP, video streaming, call clocking, etc. Can't find anything in the SWITCH official cert guide that explains this.

S0crates · March 2010

This is the usual order of prioritization. The switch book isn't going to cover QoS in any real depth. For that, check out the QoS exam.

VOIP, Video, Everything else

CiskHo · March 2010

S0crates wrote: »

This is the usual order of prioritization. The switch book isn't going to cover QoS in any real depth. For that, check out the QoS exam.

VOIP, Video, Everything else

Thanks. I just read another thread in the CCNA:Voice forum saying that highest priority would be routing protocols and STP followed by voice. Do you disagree? Thanks in advance.

Forsaken_GA · March 2010

you don't have to worry about setting qos for those things, the router does it automatically (even if you have no other qos policies defined). Certain types of packets are marked with ip precendence 6 or 7 by the router automatically. They always egress out of the priority queue, even if you don't configure one (with no qos policy defined, all the other traffic is treated as best effort). If you configure any queuing method with a priority queue, it will share it with the important traffic by default

it's good to know the proper precedence, but the only thing you really need to worry about classifying and prioritizing is user generated traffic

CiskHo · March 2010

Forsaken_GA wrote: »

you don't have to worry about setting qos for those things, the router does it automatically (even if you have no other qos policies defined). Certain types of packets are marked with ip precendence 6 or 7 by the router automatically. They always egress out of the priority queue, even if you don't configure one (with no qos policy defined, all the other traffic is treated as best effort). If you configure any queuing method with a priority queue, it will share it with the important traffic by default

it's good to know the proper precedence, but the only thing you really need to worry about classifying and prioritizing is user generated traffic

I must not be wording my question properly but I'm trying my best not to violate the NDA. I took the test Monday and I can assure you that knowing which types of data need higher priority and IN WHICH ORDER from highest to lowest priority is a topic worth knowing. I agree that knowing how to configure the QoS settings for the different data types (net traffic) is not needed. Unfortunately I have not been able to find a hierarchial list in any of my study material yet. I've gone back through the Off Cert Guide SWITCH book and this info is not in there.... or I am blind.

Forsaken_GA · March 2010

Well, then you've learned an important lesson - Don't trust a single study source, and in particular, don't trust the official exam cert guides. The information you seek is pretty trivial to find on cisco's site with the use of google

CiskHo · March 2010

Forsaken_GA wrote: »

Well, then you've learned an important lesson - Don't trust a single study source, and in particular, don't trust the official exam cert guides. The information you seek is pretty trivial to find on cisco's site with the use of google

Yep, $200 lesson to learn that CiscoPress "Official Certification Guides" do not include even close to all the info needed for the exam.

What phrase would you search for? I've been looking on Cisco with little luck. The closest thing I have found to being of use is a wiki entry... and last time I mentioned a wiki entry you said how flawed using wiki was.

Anyone know if this stuff is covered in the BCMSN books?

EDIT:
Looks like wiki to the rescue:

QoS priority levelsPriority LevelTraffic
0 (lowest)Best Effort
1 Background
2 Standard (Spare)
3 Excellent Load (Business Critical)
4 Controlled Load (Streaming Multimedia)
5 Voice and Video (Interactive Media and Voice) [Less than 100ms latency and jitter]
6 Layer 3 Network Control Reserved Traffic [Less than 10ms latency and jitter]
7 (highest)Layer 2 Network Control Reserved Traffic [Lowest latency and jitter]

QoS Traffic-Type Prioritizations?

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