[c-nsp] pros and cons for IPTV multicast in rosen-mvpn vs GRT

[Adam Vitkovsky]

> here we talk about converging the MDT S,G
And this is something I'm not quite sure how it works during the failure. 
For afi mdt the "advertise best-external" should work but "additional paths
install" is not an option. 

I tried to lab a primary-egress-PE-CE link failure in redundantly connected
CE acting as RP and Source. 
And I was expecting the primary egress PE would perform sort of a
local-repair and send triggered join towards the secondary PE resulting in
Data-MDT between the PEs until BGP converges. 
That did not happen though and only after the ingress PE received withdraw
about the source from the primary egress PE, the ingress PE sent the join
towards the secondary egress PE. 

Right the iACLs would be the only choice for global routing table solution. 



adam
-----Original Message-----
From: Oliver Boehmer (oboehmer) [mailto:oboehmer at cisco.com] 
Sent: Monday, February 18, 2013 5:58 PM
To: Adam Vitkovsky; cisco-nsp at puck.nether.net
Subject: Re: [c-nsp] pros and cons for IPTV multicast in rosen-mvpn vs GRT

 
>> easier to reduce loss-of-connectivity after link/node failures using 
>> IGP
>Fast Convergence compared to BGP-based convergence.
>Yes the convergence time would be slower I suppose as a mere addition 
>of another protocols to the picture.
>Though if you consider the whole LoC timeframe the IGP or BGP 
>convergence is one of the smallest portions -compared to the PIM 
>convergence time.

well, that really depends on the failure and platform, but BGP control-plane
convergence is generally a magnitude higher than PIM. So I would not
discount this if you're after sub-second convergence. IOS-XR and halfway
recent IOS /XE releases use an source-based, event-triggered RPF check and
will be able to send out the required PIM Joins quite fast, so the time
difference of BGP vs. IGP will make a difference..
Core link failures would still be handled quickly, here we talk about
converging the MDT S,G..
 
> 
>
>> Why do you consider putting it into a VRF?
>Well the main concern my boss has is the exposure of core/global 
>routing table to set-top-boxes -as a potential attack vector

Hmm, if the global routing is limited to the IP-TV Vlan, locking it down via
generic ACLs is easy as the traffic sources and type will be very limited.

	oli
 
>-----Original Message-----
>From: Oliver Boehmer (oboehmer) [mailto:oboehmer at cisco.com]
>Sent: Monday, February 18, 2013 4:25 PM
>To: Adam Vitkovsky; cisco-nsp at puck.nether.net
>Subject: Re: [c-nsp] pros and cons for IPTV multicast in rosen-mvpn vs 
>GRT
>
> 
>>Are there any cons for running IPTV in draft-rosen-mvpn as opposed to 
>>global routing table
>
>current implementation makes it generally easier to reduce 
>loss-of-connectivity after link/node failures using IGP Fast 
>Convergence compared to BGP-based convergence when the mcast sources/TV 
>headends are visible in BGP. You can also use p2mp-TE-FRR when mcast is 
>in the global routing table (not sure if things have changed there). 
>MoFRR is also targeted for PIM deployments in the global table, and 
>some live-live approaches might not work as well if the sources aren't 
>visible from the core/P nodes.
>
>Why do you consider putting it into a VRF?
>
>I acknowledge that reasoning is highly dependent on specific network 
>topology and requirements..
>
>	oli
>
>