Given the attention MPLS-TP has received in the industry, it is worthwhile to discuss how this technology is different from MPLS. So here is a listing of the differences between the two.
1. MANAGEMENT PLANE SETUP :
LSPs in MPLS-TP can be setup without the use of control plane purely through the management plane. Quite opposite than MPLS which would need routing protocols or RSVP in case of MPLS-TE to set up LSPs. It is as if someone is sitting in the NOC and provisioning the LSPs from NMS centrally.
2. BIDIRECTIONAL LSPs:
Quite common in transport world is to have bidirectional Paths for circuits. In IP world, a traffic setup between two nodes can actually take any path if there is mesh available; not true about MPLS-TP. Though MPLS-TP does support unidirectional LSPs it is the bidirectional LSPs mode for which the transport world will adopt it.
3. CONTROL PLANE IS NOT MANDATORY:
MPLS-TP can be run without the assistance of control plane which is absolutely a MUST HAVE for the MPLS environments. With MPLS-TP paths are setup by the NMS and downloaded into network elements.
4. IN BAND OAM:
All the necessary OAM information is carried inside the MPLS-TP frame; this is called in-band and also termed as ” fate sharing”. Again it is different from the MPLS where this OAM info is carried Out of Band.
5. NO IP FORWARDING:
MPLS-TP can run in an IP free environment; what does it exactly mean ? In traditional routers the IP is run on the interfaces since there is a need for the exchange of the out-of-band control messages. MPLS-TP can be run without IP in the forwarding plane.
5. SEPERATION OF MANAGEMENT/CONTROL AND DATA PLANE
The failure of control plane in MPLS can affect traffic while this is not true for MPLS-TP. Failure of management plane in MPLS-TP will not affect the data forwarding.
Very Informative Faisal. Many thanks for sharing. Your blogs provide very good insights and make us understand in easy way. The explanation provided in simple way helps in understanding the concepts easily.
Thanks Abdul Rauf ! for regularly visiting my blog
Hi,
Can u tell me,when we are IGP in MPLS -TP then OAM information will be inband or outband.
BR
US
Hello Upendra,
There is no IGP in MPLS-TP. It runs without IGP, configured statically from NMS
Rgds,
Faisal
Hi Faizal,
Nice article, but How an NMS statically configure and discover nodes in MPLS-TP Network without an IGP? IGP is underlying even for an NMS to setup such static routes.!
Hi Thanseer, IGP is only necessary for dynamic control plane between nodes. NMS can use other protocols to reach, discover and configure the nodes. ( such as SNMP and others). Static configuration using MPLS-TP does not need any dynamic control plane between the nodes. The nodes do not need to find out best routes to the destination as the NMS has the knowledge about the network and routes so in short the network becomes simple to operate. There are although some vendors that have an MPLS-TP version but they run IGP under the hood.
Hi Faisal,
I have one question which one is more suitable for Data Center Connectivity(Banking Sector) as 1 GE link,either we should go for IP MPLS or MPLS TP.
Br
Javed
Hi Javed,
Both are not good. DWDM is better. But if you have to choose between the two. MPLS-TP is better for such point to point connectivity
Thank you very much.
Very informative…
Thanks Protus that you found useful
thanks Protus
Hi Faizal
Nice articles, some view points from my angle.since in IP/MPLS the choice of configuration for co-routed bidirectional LSP, what is the real advantage here of having such Technology i.e MPLS-TP. some services need both flexibility and capability.
Also, Control plane failure will result affect traffic, but what cause a control plane failure in normal. if some thing can cause control plane failure inside a router extern factor example, also can cause inside MPLS forwarding plane too, also, in TP, if management plance failure, there is a high chance for that since, it is an NMS sitting somewhere in DATA centre, which can cause outages, but how it is possible to access such large network in a failure situation of management plane. some thoughts !
Co-routed bidirectional path is predictable and easy to configure. IP/MPLS can have both bidirectional LSPs as well as unidirectional LSPs. However MPLS-TP has only bidirectional LSPs.
To your second point. Management plane always has back up ( NMS 1+1). In the unlikely chance of having both NMS down, the forwarding plane will work ( no impact to traffic), but you will lose visibility of the network as well as loss of a way to configure the network.