Bonded T-1 Configuration Questions

isabellat · ‎02-18-2013

I have never bond that many T1s in an office so I need a little help. One of our office currently have

(4) T1s bonded together giving them 6 Mbps total bandwidth, we will be adding 3 additional T1s to the

existing bundle that will give them a little over 10 Mbps total bandwidth. The reason we didn't go with

AVPN 10 Mpbs Ethernet is because they do not have this service available. Since I don't have a spare

router to play with, I wonder if anyone have any idea what the configuration will be.

Here are the info for the existing configuration and equipment:

Router - 2911
WIC - (2) VWIC2-2MFT-T1/E1 (one in slot 0 and the other in slot 1)

Current configuration:

card type t1 0 0
card type t1 0 1
!
no network-clock-participate wic 0
no network-clock-participate wic 1
!
controller T1 0/0/0
cablelength long 0db
channel-group 0 timeslots 1-24
!
controller T1 0/0/1
cablelength long 0db
channel-group 0 timeslots 1-24
!
controller T1 0/1/0
cablelength long 0db
channel-group 0 timeslots 1-24
!
controller T1 0/1/1
cablelength long 0db
channel-group 0 timeslots 1-24
!
interface Serial0/0/0:0
bandwidth 1536
no ip address
encapsulation ppp
ppp multilink
ppp multilink group 1
fair-queue
max-reserved-bandwidth 100
!
interface Serial0/0/1:0
bandwidth 1536
no ip address
encapsulation ppp
ppp multilink
ppp multilink group 1
fair-queue
max-reserved-bandwidth 100
!
interface Serial0/1/0:0
bandwidth 1536
no ip address
encapsulation ppp
ppp multilink
ppp multilink group 1
fair-queue
max-reserved-bandwidth 100
!
interface Serial0/1/1:0
bandwidth 1536
no ip address
encapsulation ppp
ppp multilink
ppp multilink group 1
fair-queue
max-reserved-bandwidth 100
!
interface Multilink1
bandwidth 6144
ip address 192.168.121.254 255.255.255.252
ip flow ingress
delay 2000
ppp multilink
ppp multilink group 1
ppp multilink fragment disable
no cdp enable
max-reserved-bandwidth 100
!

I will be adding (1) VWIC2-2MFT-T1/E1 in slot 2 and (1) WIC-1DSU-T1 V2 to accommodate the (3)

additional T-1, can someone tell me if this final configuration correct the (7) bonded T1s? I'm also

not sure what the bandwidth will be in interface Multilnk1.

New Configuration:

card type t1 0 0
card type t1 0 1
card type t1 0 2
card type t1 0 3
!
no network-clock-participate wic 0
no network-clock-participate wic 1
no network-clock-participate wic 2
no network-clock-participate wic 3
!
controller T1 0/0/0
cablelength long 0db
channel-group 0 timeslots 1-24
!
controller T1 0/0/1
cablelength long 0db
channel-group 0 timeslots 1-24
!
controller T1 0/1/0
cablelength long 0db
channel-group 0 timeslots 1-24
!
controller T1 0/1/1
cablelength long 0db
channel-group 0 timeslots 1-24
!
controller T1 0/2/0
cablelength long 0db
channel-group 0 timeslots 1-24
!
controller T1 0/2/1
cablelength long 0db
channel-group 0 timeslots 1-24
!
controller T1 0/3/0
cablelength long 0db
channel-group 0 timeslots 1-24
!
interface Serial0/0/0:0
bandwidth 1536
no ip address
encapsulation ppp
ppp multilink
ppp multilink group 1
fair-queue
max-reserved-bandwidth 100
!
interface Serial0/0/1:0
bandwidth 1536
no ip address
encapsulation ppp
ppp multilink
ppp multilink group 1
fair-queue
max-reserved-bandwidth 100
!
interface Serial0/1/0:0
bandwidth 1536
no ip address
encapsulation ppp
ppp multilink
ppp multilink group 1
fair-queue
max-reserved-bandwidth 100
!
interface Serial0/1/1:0
bandwidth 1536
no ip address
encapsulation ppp
ppp multilink
ppp multilink group 1
fair-queue
max-reserved-bandwidth 100
!
interface Serial0/2/0:0
bandwidth 1536
no ip address
encapsulation ppp
ppp multilink
ppp multilink group 1
fair-queue
max-reserved-bandwidth 100
!
interface Serial0/2/1:0
bandwidth 1536
no ip address
encapsulation ppp
ppp multilink
ppp multilink group 1
fair-queue
max-reserved-bandwidth 100
!
interface Serial0/3/0:0
bandwidth 1536
no ip address
encapsulation ppp
ppp multilink
ppp multilink group 1
fair-queue
max-reserved-bandwidth 100
!
interface Multilink1
bandwidth 6144
ip address 192.168.121.254 255.255.255.252
ip flow ingress
delay 2000
ppp multilink
ppp multilink group 1
ppp multilink fragment disable
no cdp enable
max-reserved-bandwidth 100
!

Any help regarding this configurations will be greatly appreciated.

Peter Paluch · ‎03-01-2013

Hello Isabella,

I know this answer comes in late but I hope you will still be able to read it.

Have you already implemented this solution? It looks correct to me. The basic principle with adding new member links to Multilink PPP bundles is very easy - you simply add the new interface using the ppp multilink group 1 to the Multilink1 bundle, and that's it.

The bandwidth on the Multilink1 interface should be configured to 7 x 1536 = 10752 kbps.

Best regards,

Peter

isabellat · ‎03-02-2013

Hi Peter,

Thank you so much for your response.

I was certain this is how the I should configure the additional T-1s, but wanted input from people with more experience than I am since I have never bonded that many T-1s together. I also was not sure how to calculate the bandwidth of the Multilink1 interface and this really help as I've seen many ways in the past, and nothing make sense.

I am scheduled to turn up the new T-1s this coming Friday with our service provider so I will post the results after this is done.

Thank you again for your input, it is very much appreciated.

Regards,

Isabella

Peter Paluch · ‎03-02-2013

Hello Isabella,

You are welcome. As for the number of links bonded using MLPPP, the protocol itself imposes no limits. In fact, the MLPPP protocol does not even care if the links are of the same speed or type. The only limitation may be imposed by the router itself - the technical and perhaps IOS-based limitations. I am not aware of any, though, so let's hope this will work nicely for you. Just perhaps a recommendation - always add one additional link to the bundle at a time, then verify using show ppp multilink whether the link has been added successfully, and then proceed to adding another link.

Just wondering - what other suggestions for bandwidth capacity computation did you encounter?

Best regards,

Peter