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New Member

QoS (CoS) and Q-in-Q (dot1q-tunnel)

Hi,

I am looking for a document which describes the procedures and connections between QoS and Q-in-Q. Something like "NAT order of operation".

Points I am interested in are for example:

- Which CoS value is set in the outer VLAN tag?

- Which VLAN tag does 'mls qos trust cos' trust?

- Would the CoS value of the inner VLAN tag be inherited/passed to the outer VLAN tag?

I am mainly using Cat3560 and Cat3750 with IOS 12.2(25)SED1 IP-Base.

kind regards

Mark

2 REPLIES
Bronze

Re: QoS (CoS) and Q-in-Q (dot1q-tunnel)

802.1Q tunneling is a 802.1Q-in-802.1Q technique. It retags the tagged packets from a customer port with a VLAN ID assigned to that customer while preserving the original customer VLAN IDs inside the tunnel.Refer URL for QoS feature

http://www.cisco.com/en/US/products/hw/switches/ps4324/products_configuration_example09186a0080722cdb.shtml

New Member

Re: QoS (CoS) and Q-in-Q (dot1q-tunnel)

Hi,

thanks for your reply. Unfortunately this isn't the thing I'm looking for. What I'm trying to find is a description of how QoS and Q-in-Q play togehter. Something like:

- paket with 'inner' vlan tag comes in

- new 'outer' vlan tag is added to paket

- CoS value of 'inner' vlan tag is copied to 'outer' vlan tag

- qos subsystem manipulates / acts on cos value of 'outer' vlan tag

- and so on ...

So if someone out there knows how this really works, it would be nice if she/he would drop me a line

thanks in advance and kind regards

Mark

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