DSL/MAC encapsulation routing through Cisco DSL wic

bschmi · ‎09-05-2008

I have been trying to cut-over a customer site from a thomson DSL modem into cisco router fast ethernet connection........to a DSL/MER link directly into a cisco 2811 DSL wic card. All attempts (various configs) have failed thus far.

Two questions:

1. What is MER (mac-encapsulation routing)?

2. How should I configure a DSL wic ATM interface to a MER/DSL circuit (encapsulation....etc)?

Thanks in advance.

Giuseppe Larosa · ‎09-05-2008

Hello Bradley,

1. What is MER (mac-encapsulation routing)?

I've found this explanation on the user guide of a VoIP product

MAC Encapsulation Routing (MER) lets the IAD route IP addresses on the RFC 1483 bridged link. NAPT function is supported to allow multiple private IP addresses on the LAN to share a public IP address.

To set up MER service, configure the common fields, and then enter the IP Address and Subnet Mask under the MER section of the screen. Click on the Add button to add the entry.

see

http://www.zhone.com/support/manuals/docs/18/1862-A2-GB20-10.pdf

pag .33

in the window shows LLC/SNAP so it is aal5snap on cisco.

It looks like it can be a form of IRB = integrated routing and bridging with NAT or PAT.

I would start with a simple RFC1483 routed config

int atm0

no ip address

int atm0.1 point-to-point

ip address x.x.x.x

ip nat outside

pvc z/w

enc aal5snap

int fas0/0

ip nat inside

ip address p.p.p.p

if this doesn't work consider to use IRB

int bvi 1

ip address x.x.x.x

ip nat outside

int atm0.1 point-to-point

no ip address

bridge-group 1

pvc z/w

enc aal5snap

bridge 1 protocol ieee

bridge 1 route ip

Hope to help

Giuseppe