LAN extension Design

[samorange]

A Customer has a layer2 switch as the edge device, connected directly to the Metro Ethernet Provider (LAN extesnion). The Metro Network is connected to an ATM Cloud which in turn connected to another Metro area.

as follows:-

customer CPE switch A<-->SP Ethernet Swtich<--> SP ATM Switch<-->ATM Cloud<--->SP ATM Switch<-->SP Ethernet Switch<-->customer CPE switch B

My question is how the customer will configure his VLAN on the edge switch .. Can he configure any vlan ID or he has to comply/align with the VLAN mapped on the ATM VC by the provider. Please advise as it is really confusing me. Thanks

[swaroop.potdar]

1) If you are doing a QinQ then you simply allocate a VLAN for a given customer, and then Bridge that Vlan across your ATM cloud to the other side.

2) If you are not doing QinQ then yes the customer have to map to the VLAN being bridged over by the ATM VC.

HTH-Cheers,

Swaroop

[samorange]

If the the proivder is not using QinQ then let us take an example.

Assuming the proivder is using vlan 202 mapped to the ATM VC so he has to use a subnet that can accomadate the customer hosts /24 or /26 ?? and then the customer will use the same vlan id 202 for his hosts and also has to a gateway ip address in the same subnet say 192.168.202.1 ( can that be his router at the other end of the ATM VC.. )

please advise

[swaroop.potdar · Accepted solution]

[CU CPE SW-A ->Vlan 202 - (ip range /24/22 anything] <-Trunk/Access-> SP SW<- Vlan-VC MAP/Bridge-> SP ATM SW<-->ATM Cloud<--->SP ATM SW<-Vlan-VC MAP/Bridge-> SP SW <-Trunk/Access-> [ (ip range same as in SW-A CPE) CU CPE SW B ]

The hosts can be on CPE SW-A and gateway can be on CPE SW-B.

For eg: hosts in vlan 202 in SW-A have ip in say range 10.0.0.2 - 254 - DF-GW --> 10.0.0.1

DF-GW can be in CPE SW-B in same Vlan but, and use the IP in the same range i:e 10.0.0.1 and everyone can communicate.

To keep it simple just treat your connection between CPE SW-A and CPE SW-B as normal cable connecting the switches and you have same vlan assigned to this cable at both the switches.

HTH-Cheers,

Swaroop

[samorange]

Hi Swaroop:

Can I map multiple VLANs to one ATM VC ?

and

Can I map more that one VC to a single vlan ( multiple destinations)??

Please advise