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DiffServ vs. 802.1p

I'm a little confused with these two technologies. Can someone provide a brief comparison or maybe a link to a good article on when each should be used?

Thanks,

Diego

1 ACCEPTED SOLUTION

Accepted Solutions
Super Bronze

Re: DiffServ vs. 802.1p

Hi

Basically - 802.1p is a layer 2 QoS marking... so it's only present on the link between (for example) a phone and the switch, at which point it is stripped off (but may be re-written on exit from the switch). It's usually part of the dot1q or ISL trunk header.

DiffServ on the other hand is a marking contained in the layer 3/IP header. This is what you'll use over WAN or any other routed connection, but you can also use it on a LAN.

802.1p has only 7 possible markings, diffserv has a range of 64 so is a lot more flexible. A lot of the advanced QoS models use diffserv throughout as it allows more granular QoS.

See this for a good reference:

http://www.cisco.com/application/pdf/en/us/guest/netsol/ns432/c649/ccmigration_09186a008049b062.pdf

Regards

Aaron

Please rate helpful posts...

Aaron Please remember to rate helpful posts to identify useful responses, and mark 'Answered' if appropriate!
1 REPLY
Super Bronze

Re: DiffServ vs. 802.1p

Hi

Basically - 802.1p is a layer 2 QoS marking... so it's only present on the link between (for example) a phone and the switch, at which point it is stripped off (but may be re-written on exit from the switch). It's usually part of the dot1q or ISL trunk header.

DiffServ on the other hand is a marking contained in the layer 3/IP header. This is what you'll use over WAN or any other routed connection, but you can also use it on a LAN.

802.1p has only 7 possible markings, diffserv has a range of 64 so is a lot more flexible. A lot of the advanced QoS models use diffserv throughout as it allows more granular QoS.

See this for a good reference:

http://www.cisco.com/application/pdf/en/us/guest/netsol/ns432/c649/ccmigration_09186a008049b062.pdf

Regards

Aaron

Please rate helpful posts...

Aaron Please remember to rate helpful posts to identify useful responses, and mark 'Answered' if appropriate!
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