[j-nsp] Segment Routing Real World Deployment (was: VPC mc-lag)

[adamv0025 at netconsultings.com]

> Of Pavel Lunin
> Sent: Monday, July 09, 2018 11:46 PM
> 
> However my original point was rather about pseudo-wires than VPLS. I
> mean, I don't see a lot of pseudo-wires in the wild. Mostly because PW is
a
> kind of hard to sell. Customers can be of two types: those who love Metro
> Ethernet and those who don't. It's true for real customers, whose
> requirements are amplified by the sales people, and internal
infrastructure
> folks.
> 
> Those who love L2 because "it's better and easier" usually don't know what
a
> pseudowire is. And they just don't care. "Like a switch" is what they are
> looking for.
> 
> Those who avoid metro-ethernet just don't need pseudowires, certainly
> automesh Kompella-style. L3VPN works well for them, or they buy L1
> between their routers, or go EVPN.
> 
> A pseudo-wire is a kind of side application in my experience, even though
> technically it's simple and powerful. Not that it doesn't exist as a
commercial
> service, but mostly used for internal infrastructure needs on an
occasional
> basis.
> 
> So I tend to think, that if your business can make money out of pseudo-
> wires, it's not about your network design, you are just lucky ;)
> 
Speaking for the Carrier Ethernet market here,

There was a huge market potential several years ago for p2p PWs (I don't
really know what the situation is nowadays). 
It all started the same way as the shift from leased lines to Frame-Relay. 
Leased lines where expensive and not very profitable for service providers
-so instead of selling a leased-line between point A and B to one customer
SPs put a FR switch at each end and sold it to 10 customers.
Same happened several years ago with operators who owned their own fibres or
had enough lambdas -you can't make good money selling wavelengths -and
besides it's not like people need SONET or SDH -everyone converged on
Ethernet, so what do you do? You stick a PE router at each end of the lambda
and you sell it to 10 customers instead.
Customers can't tell the difference cause this thing is like an Ethernet
cable between point A and point B -and you sell it at a much lower price
point in comparison to wavelength so it becomes very attractive to a lot of
folks who could not afford a dedicated wavelength or fibre.
The p2p PW were the killer app, for providing services to all the smaller
SPs that wanted to expand their MPLS backbones across the country or even to
other countries but did not quite qualify for dedicated fibre or lambda to
some remote places that we had covered. But this was also used by large SPs
like at&t, etc.. to extend their (mostly) PE-CE links to places where they
did not have their own infrastructure. 
ENNIs to other Carrier-Ethernet providers and of course MEF standardization
made it really easy to stretch these PW services all over the place.
And we all did use just simple p2p PWs, no mac learning, just simple what
goes in goes out including L2CPs. 
This was carriers providing services to other carriers.

Now with corporate customers or  DC folks the story was always "yeah this
l2vpn stuff is hot right now we need that too", but if you talked to them it
turned out what they really needed was just a series of p2p links -no one
wanted to have mac limits imposed on them or be haunted by the complexity of
mp2mp and large l2 domains.  

So where we used what someone might call VPLS (bunch of PW into a BD) was
primarily for internal services for l2 backhauling.   

As you can see my experience is quite the opposite, that is no really much
of mp2mp or p2mp VPLS style services, but a whole lot of p2p PWs all over
the place. 

adam        

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