[c-nsp] ASR902 vs ME3800X

[Adam Vitkovsky]

> From: Mark Tinka [mailto:mark.tinka at seacom.mu]
> Sent: 24 March 2015 11:56
> Agree, but remember every node you add into the IGP creates state; and
> you want to run pw's all over the place, that states need to be held in FIB.
> 
> I wouldn't say l3vpn prefixes are the majority in most MPLS networks, as
> some MPLS networks focus on l2vpn's (Martini, not BGP), which would mean
> less l3vpn BGP state to be held. So this one depends.

Fair point I agree but hierarchy is not the way to go. We should not be forced into troublesome topologies just because FIB space worth of 20k prefixes is considered to be enough for the access layer. 

> I don't like Route Leaking, but if the 4-port ASR920 does not have enough FIB
> to hold my entire IGP table + some l3vpn BGP routes, it's a non-starter. I'm
> not in the mood to run pw's to an "intelligent" box in the core to instantiate
> services from there. Might as well run a Layer 2 network :-).
> 
What we did is we end up stacking boxes into locations that required more FIB space.

 
> The main problem with a Layer 2 ring is protection. Easier if the ring is
> terminating on the same upstream node (but still a b**ch), way harder if the
> ring is terminating on different upstream nodes (a real b**ch, but what sales
> droids push to customers).
> 
> Any way you cut it, Layer 2 access points that are not point-to-point with
> their upstream nodes in nature are a real PITA to operate.

Yeah hence the move to push IP as far as possible and possibly take MPLS along with it.
 
> I'm giving EVPN two more years (like SDN) to settle down before we can
> separate the wheat from the chaff. Too much handwaving at this time,
> especially if you run a multi-vendor network.
> 
> To be honest, I'm not unhappy with Martini l2vpn pw's.
> 
> Mark.


I'm looking forward for the PBB element from the scaling perspective as I don’t want to be carrying bare MAC addresses in RIB/FIB (have enough problems with VPN prefixes). 
And also multicast distribution is much better with mLDP compared to full mesh of PW so I don't need to try to sell a hybrid two services solution for L2VPN+Multicast(via L3VPN). 
 
Don't even get me started with SDN :) 
To me it's just a woo woo, sorry about the advert but to me it's exactly like that: https://www.youtube.com/watch?v=sr_EtMhM3fg
Until they have ASICs capable of doing routing/traffic engineering based on application requests in real time for millions of flows at multiple 10Gbps rates it's all just a nice dream. 


adam
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