What does VLAN tagging actually achieve?

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ripdog

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#144170 9-May-2014 15:14

This is something I've been wondering for a while. I understand that both xDSL and UFB connections generally require VLAN tagging on the WAN port in NZ.

There must be some advantage to this, considering the huge restrictions it places on what gateway equipment can be used at the consumers end. Surely it isn't just flipping a bit on outgoing packets?!

plambrechtsen

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#1040884 9-May-2014 15:17

The main reason for tagging everything VLAN 10 means that you can run multiple services over the same physical interface on different VLANs and can QOS prioritise say voice traffic if you move it over a different vlan and tag it with a different .1p priority.

You can't do anything like .1p on untagged interfaces.

ripdog

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#1040887 9-May-2014 15:24

plambrechtsen: The main reason for tagging everything VLAN 10 means that you can run multiple services over the same physical interface on different VLANs and can QOS prioritise say voice traffic if you move it over a different vlan and tag it with a different .1p priority.

You can't do anything like .1p on untagged interfaces.

Ah, to use the CIR? Fair enough.

Does the router need to do the .1p tagging? Should it be combined with local QOS to ensure that priority traffic gets through on a saturated line?

I have an ASUS rt-AC66U. It supports VLAN tagging, but I can't see any support for .1p tagging...