I work for a small CLEC, we have been doing FTTP for 5 years now but are
getting ready to update our core network and introduce IPTV services. Cisco
has been recommending the Cisco 7600 as our core router. My concern is that
cisco told us that in the event of an RSP failover the 7600 could take up to
30 seconds to begin routing packets again, this seems wrong to me since my
old Extreme Networks BD 6808 can do failovers and rebuild route tables in
under 5 seconds but?? More recently I have been reading up on the ASR 9000
however and it appears that it would be better sized for our company than
the 7600. A few questions I have for the group.
1. Has anyone used the ASR 9000 in place of a Cisco 7600?
2. Is the ASR 9000 Carrier ready? Meaning 5x9's of availability, few
component failures, solid software...etc
3. Has anyone had issues where it took the 7600 30 seconds to start routing
again after an RSP failover?
Thanks,
Nick
What about 7600-S models ?
I think Cisco is claiming that Cisco 7600-S (7606S, etc...) chassis is
ready for less than 50 ms switching time with right software.
For routing, you can setup graceful restart or something like that.
For Cisco ASR9000, I couldn't say much, because it is new product.
When I checked Cisco product lines around January 2009, it wasn't there.
So I consider it as still beta test product at customer's expense. 
Alex
Nick Colton wrote:
This question would likely be better answered on cisco-nsp.
But the asr9k provides a better roadmap than the 7600/6500 platform. These are now quite old platforms in the overall lifecycle. The 9k also runs xr which is either an asset or liability depending on your network.
Me? I always want a box that provides good diagnostics and protected memory over one that does not. Bugs happen, software is imperfect. I want a device that provides the best possible debuging information when it comes to support time.
These items are not there in regular ios, and IMHO ios-xe does not really qualify (but is better, just like the ion/modular 6500 code).
Jared Mauch
For NSF/SSO mode the 7600 is claimed to do Sup failover in 0-3 seconds
(which jives pretty well with my experience), but with some caveats. I
think it needs to rebuild its RIB tables, which may take on the order
of 30+ seconds, after a failover and can only keep forwarding traffic
based on the state of the tables at the point of the failover. NSF/SSO
mode has a couple limitations (only BGP, OSPF, and IS-IS supported),
doesn't support IPv6 multicast, etc.
30+ seconds failover time sounds more like RPR/RPR+.
You can find a fairly good overview of this on CCO:
* NSF/SSO: http://www.cisco.com/en/US/docs/routers/7600/ios/12.2SXF/configuration/guide/nsfsso.html
* RPR/RPR+: http://www.cisco.com/en/US/docs/routers/7600/ios/12.2SXF/configuration/guide/redund.html
I run these as essentially switches with very simple LAN routing so I
can't really tell you whether there are any huge honking caveats when
you use them as actual routers (i.e. WAN/SP type applications). I know
there have been some complaints about buggy IOS versions,
unpredictable feature/module support, and the notorious 6500 vs. 7600
platform split (thank you ever so much for that one Cisco, really).
I've been pretty happy with the platform over the years, but while
it's still got plenty of oomph for my applications it is getting to be
a quite old platform. If I were to start looking at building something
new (i.e. no existing platform investment to take into account) I'd
probably be looking at Nexus for datacenter and ASR for anything
router-ish. I think 6500/7600 will still scale further up
(significantly so, iirc) and is more flexible than the ASRs (I view
the ASRs competing/replacing the 7200/7300 rather than 6500/7600), but
if you're looking at anything resembling a clean slate you'll probably
want to evaluate those alternatives.
Anyways, if you're going with Cisco then asking on the cisco-nsp list,
as was suggested elsewhere, is probably not a bad idea.
HTH, -link