[c-nsp] ACI vs Segment Routing in DC

[adamv0025 at netconsultings.com]

> Harivishnu Abhilash
> Sent: Friday, November 1, 2019 11:45 AM
> 
> Classification:Public
> 
> Hi Guys,
> 
> Anybody has experience of deploying Segment Routing in DC. Have seen its
> deployment in WAN. But just couldn't understand its future in DC as ACI is
> already an established product in DC...
> 
> Amy thoughts would be great
> 
Well ACI is Cisco specific, Juniper has Contrail, Arista has ..whatever, as
you can see each one of these vendor has its own proprietary, DC only,
solution along with the whole ecosystem for automation.

Now SR in DC is no different to SR in any other MPLS core/WAN. Same as VXLAN
or MPLSoUDP/GRE is going to look and feel the same wherever it's deployed.
-the difference is only in the vendor's proprietary complete vertical
automation stack you'll get with the vendor's solution. 
(and currently none of the DC automation vertical stacks out there can then
be extended to manage your MPLS core or any other parts of your
infrastructure.)

Comparison of SR vs ACI(VXLAN) on a technical level,
VXLAN does not support Traffic-Engineering (TE) (note: service chaining is
traffic engineering) 
VXLAN does not have any solution for mice vs elephant flows (no support for
TE)
VXLAN does not have any solution for micro-segmentation (the answer is use
lengthy access-lists like in 90's -but this time around ACLs are automated
so don't worry ) 
VXLAN to MPLS interface is clumsy to say at least.
- In MPLS networks all the above is solved with the use of MPLS labels. 

 
 adam