Low density Juniper (or alternative) Edge

Nick Hilliard nick at foobar.org
Wed Feb 3 07:58:38 UTC 2016


David Bass wrote:
> Looking to see what others are using out there as an alternative to a
> Cisco ME3600X? Also, what other vendors out there are playing in this
> space?
> 
> Need a full MPLS stack.

Before choosing a box, you need to figure out:

- how many ports you need, and of what speed
- how much you're prepared to pay
- how much rack real estate you're ok about dedicating per box
- what sort of mpls features you need (vpls / l2vpn-pw / l3vpn / 6pe /
6vpe, etc)
- whether rich qos is a requirement
- whether you're ever going to need good quality LAG / ECMP support on
the platform
- what vendor software you're happy to work with
- whether you're ok with per port licensing

Typically the features that fall by the wayside first are: reasonable
port buffers, qos knobs and decent lag/ecmp hashing support for mpls
packets.  The qos/port buffers tend to be more of a problem on the 10G
platforms, but you didn't state whether you were interested in 1G or
10G, or how many ports you were looking for per box.

E.g. the production evolution for the me3600 is the asr920, which is
better is most aspects except for shared buffer space.  This means that
the me3600 has better qos support, if deeper buffers are what's
important.  OTOH, if you need to do fine-grained qos based on ACLs or
ports, then this platform isn't for you.

Most smaller mpls boxes don't load balance well over LAGs or ECMP
because they lack the ability to inspect deep into the packet to get
enough flow-aware entropy together to build a reasonable hash.  If all
your PE devices support flow-aware transport (rfc6391), you're fine, but
very few smaller mpls boxes support this feature.

If 10G is a requirement, then you need to make a choice between one of
the merchant chipsets (e.g. broadcom trident range) and vendor specific
chipsets.  Many of the larger vendors support the merchant chipsets
these days for 10G access, but feature support can be varied.  E.g. some
devices don't support vpls and never will.  Some are a bit behind on
product development and don't yet support features like l3vpn or 6PE or
6VPE, even though they are roadmapped.

Nick


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