[c-nsp] mlppp dot1q question

[Paul Stewart]

Thanks very much .. that gives me what I was looking for unfortunately ;)

Paul


-----Original Message-----
From: Justin Shore [mailto:justin at justinshore.com] 
Sent: November-26-09 10:57 AM
To: Paul Stewart
Cc: cisco-nsp at puck.nether.net
Subject: Re: [c-nsp] mlppp dot1q question

Paul Stewart wrote:
> Hey guys...
> 
>  
> 
> Is there any way to run subinterfaces across a MLPPP bundle in IOS?  

I'm assuming that you want to carry a couple VLANs down a MLPPP bundle, 
correct?  If so then one solution is called BCP (Bridge Control 
Protocol).  It's a fairly old protocol.  When I researched it I found 
references to it in the early 12.x code docs.  You probably don't want 
to consider it though.  Command #1 in any config guide you find is 'no 
ip routing'.  That's right; you have to disable routing on your router 
to use it.  We were evaluating the Overture ISG 140/180 Ethernet of 
bonded DS1 product when we came across it.  The OV SE told us that sure 
it interopted nicely with MLPPP on a 7200.  What he didn't mention was 
that you also had to use BCP, effectively cutting the legs out from 
under our router.  If you happen to have an old 7200 with an older CPU 
sitting around then you have a nice platform to work with.  If you don't 
and the router you spent big $$$ is also doing routing (fancy that) you 
probably don't want to use BCP.

On a side note, I recall while searching for data on BCP that it's also 
possible on platforms that use SPAs.  If memory serves me correctly you 
don't have to disable routing on those platforms.  On those platforms 
you can literally apply switchport commands to the Serial interfaces. 
It looked very slick but we didn't have SPA-capable hardware in that POP 
to work with at the time so it wasn't a solution for us.

Search cisco.com for BCP and you'll find some docs.

http://www.cisco.com/en/US/docs/interfaces_modules/shared_port_adapters/conf
iguration/6500series/76cfgt1.html#wp1159581
http://www.cisco.com/en/US/docs/interfaces_modules/shared_port_adapters/conf
iguration/7600series/76cfgsip.html#wp1182134
http://www.cisco.com/en/US/docs/ios/bridging/configuration/guide/br_bcp_ps10
591_TSD_Products_Configuration_Guide_Chapter.html
http://www.cisco.com/en/US/docs/ios/12_3t/12_3t2/feature/guide/gt_bcp.html
http://www.cisco.com/en/US/docs/ios/bridging/configuration/guide/br_bcp_ps69
22_TSD_Products_Configuration_Guide_Chapter.html

Or are you asking if it's possible to break a MLPPP bundle of a couple 
DS1s into a couple different MLPPP bundles while still maintaining some 
manner of link redundancy when spanned across the 2 (or more) DS1s?  If 
that's the case then you could look at creating multiple channel-groups 
in the controller config.  Say for example

t1 10 channel-group 0 timeslots 1-12
t1 10 channel-group 1 timeslots 13-24
t1 11 channel-group 0 timeslots 1-12
t1 11 channel-group 1 timeslots 13-24

Then put Se1/0/10:0 and Se1/0/11:0 into a MLPPP bundle and Se1/0/10:1 
and Se1/0/11:1 into a separate MLPPP bundle.  The downside is that there 
is no sharing of bandwidth between the 2 unique bundles.

Best of luck
  Justin