The MPLS-OPS Archive

[Mathew Lodge <mathew@cplane.com>]

At 08:59 PM 2/27/2002 -0800, venumadhav josyula wrote:
> I agree with you on that, it
> therotically possible to do that what you explained, since MPLS is used
> in the Core of the Networks, so only pratically possible is IP (V4 ) I am
> not sure many vendors yet support V6 or not.............

It is not just theoretically possible -- it is actually happening today.
You can carry any protocol inside an LSP. At the switching level, MPLS
doesn't care what's inside each label-encapsulated frame -- hence the
name Multi-Protocol Label Switching. The control plane (used to establish
LSPs) and the data plane (forwarding of label-encapsulated frames) are
totally independent of each other.

At the data plane, there is no reason that LSPs cannot be used to carry
any mix of protocols -- not just IPv4. You don't need some special set of
new LSPs to carry other protocols -- in fact, you'd probably want to
avoid this to reduce label space consumption. Only the LERs need to know
how to handle the MPLS encapsulations responsible for each protocol,
since they are responsible for encap/decap. As concrete examples running
in real networks today, Cisco and Juniper LERs carry both IP and Ethernet
over the same LSPs.

At the control plane, you *could* use topology information from the IP
layer (usually created by running OSPF or IS-IS protocols) to set up LSPs
-- but you don't have to. Many classical router-based LSRs do flood
topology information from an IP routing protocol into LDP to make it easy
to get an MPLS network up and running, and to establish new LSPs as links
and nodes are added.
But this is not the only way to establish LSPs. You could use a traffic
engineering tool to determine optimal LSP routes and automatically
configure all of your LSPs and never use OSPF or any other IP routing
protocol to set up LSPs.

Cheers,

Mathew

-v

  "Gowda, Sidde" <s_gowda@trillium.com> wrote:

Hi Leo
 
You can establish LSPs between routers with different L3 protocols. For eg. IPX, IPv6, AppleTalk etc..
No matter which L3 or L2 you are using, it works well. Hence it is Multi-Protocol
 
Siddu

-----Original Message-----

From: venumadhav josyula [mailto:venu_m_j@yahoo.com]

Sent: Thursday, February 28, 2002 9:28 AM

To: wang.licun@zte.com.cn; mpls-ops@mplsrc.com

Subject: Re: How to establish LSPs in the network which has different network layer protocols?

Which different networking protocols are you talking about ?

venu

  wang.licun@zte.com.cn wrote:

In the network which has different layer 3 protocols, is it possible to

establish LSPs betweent routers with these protocols? Or can we only use

multi-layered (hierarchial) labels?

Can MPLS be used to establish VPN tunnels to connect the sites which use

different layer 3 protocols?

Would you please give me you advice or recommend some documents?

Thanks a lot!

Leo Wang

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| Mathew Lodge                 | mathew@cplane.com     |
| Director, Product Management | Ph: +1 408 789 4068   |
| CPLANE, Inc.                 | http://www.cplane.com |