Solved

Understanding DSCP Values and Marking

Posted on 2012-03-18
8
1,340 Views
Last Modified: 2012-03-21
I am currently configuring Lync for our enterprise. I have it running but I want to implement QOS so that it has priority over certain data types and less than other.
These are the port ranges.

Audio      49,152 – 57,500
Video      57,501 – 65,535
Application Sharing      32,768 – 49,151
Client File Transfer       24,733 – 32,767

Now, in QOS policy, it asks for a DSCP value for each. How do I know what value to use and what it means?

If someone can explain the significance (Ive read articles but still dont really understand), it would help me out a lot.

Thanks
0
Comment
Question by:Network_Padawan
  • 4
  • 3
8 Comments
 
LVL 35

Accepted Solution

by:
mccarl earned 500 total points
ID: 37736000
Basically, it is the priority, but not necessarily in numerical order. Different values have specific meanings, and therefore specific priorities. Have a look at the Wiki for this and you will see that 0 is the default traffic and the lowest priority (best-effort), 46 is for "expedited forwarding" and will have the highest priority, and then the values in the table (10, 12, 14, 18, 20, 22, 26, 28, 30, 34, 36, 38) are for "assured forwarding" which will have a priority inbetween the default and 'expedited' but also has different classes of priority within itself.
0
 

Author Comment

by:Network_Padawan
ID: 37736043
so if i place a 46 on video and audio, what will that do for the rest of data traffic? Do I need to prioritise the rest as well?
0
 
LVL 35

Expert Comment

by:mccarl
ID: 37736050
No, that's why the 0 is default, all traffic that isn't given a specific value, will be classed as default, and will then be lower priority to your video and audio.
0
Efficient way to get backups off site to Azure

This user guide provides instructions on how to deploy and configure both a StoneFly Scale Out NAS Enterprise Cloud Drive virtual machine and Veeam Cloud Connect in the Microsoft Azure Cloud.

 

Author Comment

by:Network_Padawan
ID: 37736062
Ok, thanks, just lastly, does DSCP have anything to do with TOS? Or are they seperate things?
0
 
LVL 35

Assisted Solution

by:mccarl
mccarl earned 500 total points
ID: 37736072
DSCP is a newer concept than TOS, but it reuses the same field, in a way that is backwards-compatible to the older TOS. In the wiki link that I gave you above, it talks about this in the section on the 'Class selector' PHB, but basically use of TOS gives values that are distinct from the ones defined for DSCP.

However, if you are just setting this all up from scratch, you shouldn't need to worry about TOS.
0
 

Author Closing Comment

by:Network_Padawan
ID: 37736115
Thanks. Makes much more sense.
0
 
LVL 35

Expert Comment

by:mccarl
ID: 37736119
Not a problem!
0
 
LVL 12

Expert Comment

by:Jeff_Schertz
ID: 37750433
Take a look at this blog article which describes this concept in detail as it pertains to Lync Server:
http://blog.schertz.name/2011/08/lync-qos-behavior
0

Featured Post

Windows Server 2016: All you need to know

Learn about Hyper-V features that increase functionality and usability of Microsoft Windows Server 2016. Also, throughout this eBook, you’ll find some basic PowerShell examples that will help you leverage the scripts in your environments!

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Data center, now-a-days, is referred as the home of all the advanced technologies. In-fact, most of the businesses are now establishing their entire organizational structure around the IT capabilities.
Join Greg Farro and Ethan Banks from Packet Pushers (http://packetpushers.net/podcast/podcasts/pq-show-93-smart-network-monitoring-paessler-sponsored/) and Greg Ross from Paessler (https://www.paessler.com/prtg) for a discussion about smart network …
Viewers will learn how to connect to a wireless network using the network security key. They will also learn how to access the IP address and DNS server for connections that must be done manually. After setting up a router, find the network security…
This video gives you a great overview about bandwidth monitoring with SNMP and WMI with our network monitoring solution PRTG Network Monitor (https://www.paessler.com/prtg). If you're looking for how to monitor bandwidth using netflow or packet s…

777 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question