What is MPLS-TP and is it relevant?
At the time when I was writing my MPLS books and developing MPLS courses for Cisco, everyone was ecstatically promoting GMPLS (Generalized MPLS) as the next unifying technology of everything, making someone so fed up with the fad that he wrote the Electricity over IP RFC.
GMPLS got implemented in high-end routers, but never really took off (at least I’ve never seen or even heard about it). Obviously the transport teams found the idea of routers requesting on-demand lambdas with IP-based protocols too hard to swallow.
Few years ago, ITU-T tried to reinvent the wheel (and ride on the MPLS brand name) and started the T-MPLS effort. After a while, IETF and ITU-T managed to sort out the paperwork (including plenty of liaison notes) and started joint MPLS-TP task group and new standardization efforts.
The first MPLS-TP RFCs have already started to appear and there are numerous drafts in the pipeline, so it’s high time to take a second look at MPLS-TP and figure out what’s new and whether it’s a useful technology. I tried to do that in the MPLS and MPLS Transport Profile (MPLS-TP): The technology differences article published by SearchTelecom.
How do you thing about the OTS - with enhanced ethernet services deployment in enterprise or university? Basically ROADM with integrated ethernet switch on traditional node rooms, only two powerful routes/firewalls in datacenters with ring topology to each node rooms which will be layer 2 switched.
Would you know how many transport networks actually use GMPLS versus more traditional NMS-based provisioning?
Although this is a reply that comes more than half a year late, I hope you will still get to read it :)
I believe that the point of MPLS-TP is having a telco-kind of management and control above the network. From the service point of view, there is no difference to MPLS or MPLS-TP or T-MPLS... every one of them uses the label stack precisely in the same way. In my opinion, the difference is how do the labels (and LSPs and all the stuff) get set up in the first place, and intelligence on LSRs is needed for that.
We already have quite a lot of label-disseminating protocols: LDP, RSVP, BGP, the first two of them being heavily dependent on IGP routing protocols. Providers routinely dislike running RSVP in their networks, even if for sole purposes of MPLS-TE. So in order to actually set up a LSP, there is a lot of work to do in the control plane of a router, and synchronizing this work among lots of routers is a nontrivial task.
The other observation is that a LSR actually does not need IP for most of its data plane operations, as it is concerned with labeled packets most of the time. All the hassle with IP-based protocols is just to create the label bindings - and then, you can theoretically get rid of the IP stuff as long as you have your LFIB populated with correct entries.
In telco network, the idea of a management network above the managed nodes, and the managed nodes being "fast and stupid", has its advantages. A central node managing the network allows for complex and extensive path creation and selection between nodes because it is performed as a centralized computation, as opposed to all nodes in the network performing this computation in a distributed manner, without having a centralized point of command. This is where I see the MPLS-TP step in: as a means of controlling the LSP creation and management and removing the IP-based control plane from the network nodes and centralizing it in a single control element who is in charge of all network nodes. For example, the MPLS-TE is a complicated thing to do if lots of tunnels are to be configured in a regular MPLS network. The MPLS-TP could solve this quite easily, as all the hassle of OSPF-TE or ISIS-TE combined with RSVP-TE would simply not be necessary.
I also think that nobody is trying to reinvent the TDM or SDH by MPLS-TP. Surely, the underlying technology under MPLS is mostly packet-based, so it is almost impossible inherently to maintain the time division aspect of any TDM/SDH network. What we are getting at with MPLS-TP is having more controlled environment where the LSPs are built not by cooperation of network nodes like in today's MPLS networks, but rather by a centralized control. Reminds me slightly of LWAP/CAPWAP (although they centralize both data and control plane).
Granted, MPLS-TP also says you can use GMPLS but the 'static' way seems to be already there...? So what's new here ?
I am planning to do my masters project in MPLS-TP. Can someone give me some idea and guide me through...???