ONT - QoS Pre-Classify

Unanswered Question
Jan 19th, 2008

Hi Guys,

I hope someone can help me here. Just revising some ONT stuff before exam and realised that i do not understand when the 'qos pre-classify' command is used when implementing QoS over VPNs.

Can someone clearly expalin when exactly you use the QoS Pre-Classisfy command and when not to use it.

Forever Greatful

Stephen

PS - i'm gonna post this over in 'VPNs-General' also for a bit more exposure.

I have this problem too.
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srue Sat, 01/19/2008 - 05:58

qos pre-classify is used to identify ip header information before it passes through a tunnel (encrypted or unencrypted) for qos purposes. depending on tunnel-type, a certain amount of header information is copied, and then applied to the tunnel header, so QoS information is available as it passes through the tunnel network. Without pre-classification, the QoS bits are lost in encryption and/or packet encapsulation.

http://www.cisco.com/univercd/cc/td/doc/product/access/mar_3200/mar_conf/m032qos.htm#wp1077010

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