ISDN PRI Backup for 2 Mbps Link to Internet

[csplau]

Hi,

Anybody has any experience in using ISDN PRI for Internet link backup? I am using cisco 3620 with 1 serial link with 2 Mbps and 1 PRI ISDN module. Thanks

[dinekal]

Hi,

Yes you can have ISDN PRI as backup. You need to enable multilink PPP at your end and at the destination.

You can also configure the load at your backup PRI interface for the effective utilization of bandwidth.

Hope this helps

Dinesh

[csplau]

Any sample configuration please?

[dinekal]

Assuming you are using e1 standard, pap authentication & static routing

!

controller e1 1/0

pri-group timeslots 1-31

!

interface serial 1/0:15

ip address negotiated

encap ppp

ppp multilink

ppp authetication pap

ppp pap sent-username password

dialer string

dialer-group 1

isdn switch-type

description **** ISDN PRI ****

!

access-list 1 permit ip any

!

interface serial 0/1

ip address x.x.x.x y.y.y.y

backup interface serial 1/0:15

backup load 75

!

ip route 0.0.0.0 0.0.0.0 serial 0/1

ip route 0.0.0.0 0.0.0.0 serial 1/0:15

Good Luck

Dinesh

[csplau]

Thank you Dinesh