PPPoE over MPLS VPLS MTU

RouterOS Forwarding Protocols
1

I know it’s already been a lot of topics about this but I’m stuck! :confused:

Simple situation:

PPPOE server AC (RB1100AH)…vpls…basestation (RB433GL)
…vpls2…basestation (RB433GL)
…vpls3…
…etc…
Vpls tunnels are bridged to achieve L2 connection for PPPoE.
RB433GL have L2MTU on ethernet pots 1524 so I set MPLS MTU to 1524 on all MPLS interfaces in cloud.
And vpls tunels work (MTU and MRU 1500?), pppoe connection established with clients (SXT 5 lite) but I’m confused…
PPPoE MTU on concentrator and clients are set to 1480 (def.)

Is it 100% that MPLS MTU (and L2MTU on al interfaces in cloud) must be minimum 1526 to trnsport full frame without fragmentation?

What is best configuration im my cace (when we have limitation RB433GL l2mtu 1524 max):
PPPoE MTU (on client side and AC)?
VPLS MTU and MRU (is 1500 OK)?

I notice that some of pppoe connections drop every about 1-24h, and client upload drops to 10-100 kbps. Signals -60dBm, ccq 90-100%.
Is this posible fragmentation problem?

TNX

2

http://forum.mikrotik.com/t/solved-pppoe-via-vpls/73762/1

In this thread I have asked the same question.

3

Look @ http://wiki.mikrotik.com/wiki/File:MTUVPLS.png

Answer to your question is, yes! You need 1526 MPLS MTU to transport 1500 byte packet without fragmentation.

Wich version of router os are running your mpls routers? I have got mtu problem with some RouterOS version.

Bye