I heard the following pretty bold statement while listening to an episode of my favorite podcast: “Bringing MPLS into the data center is impractical because MPLS requires custom silicon.” Really? How about checking the Intel FM 6000 product brief first?
Broadcom Trident chipset supposedly also supports MPLS. I couldn’t verify that because Broadcom considers the capabilities of their hardware highly confidential (but if you know more, do write a comment). Absolutely refreshing for a chipset that you get in almost every ToR switch you buy.
Can we thus expect to see MPLS in ToR switches
Not likely for a number of reasons:
- Customers are not asking for MPLS. Most enterprise data center engineers tend to avoid it like a plague, and large cloud providers focus more on overlay networks, obviating the primary need for DC MPLS (although I was told one of the largest web content providers uses MPLS extremely creatively pulling it all the way down to individual web servers).
- Due to lack of customer requests, MPLS is not the primary focus of merchant silicon vendors. Even though FM 6000 supports MPLS, it needs TCAM to match MPLS labels wasting precious hardware resources – the more MPLS labels a switch supports, the fewer ACL or PBR entries it could have.
- MPLS data plane is easy (how hard is it to swap 32-bit labels?), the tricky part is the MPLS protocol stack (LDP first, then MPLS TE or MPLS/VPN), and not every vendor has one.
I totally agree (as I wrote before) that it’s highly unlikely MPLS will replace overlay virtual networks as the next-generation network virtualization technology (service providers integrating their public cloud with their MPLS/VPN service might be an obvious exception – or so Juniper and Nuage Networks hope), but please don’t claim it’s due to lack of merchant silicon support.