[c-nsp] ASR 1000 series replacement

[Tarko Tikan]

hey,

> We have a somewhat unusual scenario with thousands of CPE devices
> each using cellular interface and gre tunnel to connect to hub
> router, currently ASR 1001x. The hub router deploys NHRP map
> multicast with GRE tunnels and bgp session to each cpe device, each
> tunnel different customer vrf connected to mpls core network. There
> are hundreds of GRE tunnels.

Not really so unusual in SP environment.

> What would be logical replacement for hub router considering
> expansion and redundancy. We tried a pair of stacked Cisco 9500, and
> it performed worse than expected.

cat8500 family (non-L models). Forget the stupid naming, this is 
actually next-gen QFP and should be called asr1k+

> One solution we have is another
> router with same addressing scheme, and to rely on routing to migrate
> tunnels to this new router in the event of failure of original hub.

Anycast works and this is what we did for exactly the scenario your 
described earlier. But we found that we'd like it to be more hitless so 
we are now deploying dual tunnels from every CPE to C8500-12X headends.

-- 
tarko