Am I Right about this???

[nisha_kulkarni]

Hi there...

The main difference between layer 2 and layer 3 MPLS based VPNs is the type of customer connectivity that happens with Service Provider (SP)...In layer2 VPNs, the connectivity is simple L2 (e.g. q-in-q/VPLS) and in Layer 3 it is basically using routing protocols from CE to PE End...

Now my question is, let it be any connectivity between CE-PE...But what I'm interested in is the MPLS behaviour...It's going to be Layer 3 connectivity in MPLS cloud regardless of what mechanism is being used for CE-PE, right????????

Now I have other question....Say I have a customer A in San Jose connecting thru SP A and I have a customerB in New York Connecting thru SP B....Two different customers but belonging to SAME ENTERPRISE but connecting thru two different SPs..Can I have VPLS services offered to these two different customers of SAME ENTERPRISE thru two different SPs?????Or is that all manadatory to use only ONE service provider offering VPLS services in different Metros say San Jose,CA,VA,NY etc...????`

Sorry for asking such basic level questions, but just wanted to clear doubts in my mind...

Regards,

NISHA

[Harold Ritter · Accepted solution]

You are right in saying that no matter what MPLS services you are delivering at the edge, you need to have a layer 3 core (with an IGP, LDP and/or RSVP) as the basis of your MPLS infrastructure.

I personally don't know of any SPs specifically deploying InterAS VPLS. I don't see any reason why it wouldn't be possible though. As long as InterAS is deployed between the two SPs using IPv4 + label (usually refer to as draft RFC2547bis option 10c).

For more information on ipv4 + labels, please refer to the following documents:

http://www.ietf.org/internet-drafts/draft-ietf-l3vpn-rfc2547bis-03.txt

http://www.cisco.com/univercd/cc/td/doc/product/software/ios120/120newft/120limit/120s/120s23/fsiasl23.htm

Hope this helps,

[nisha_kulkarni]

Thanx for the answers and links Mr.Harold...

That cleared all the doubts in my mind..

Regards,

NISHA

[adityakaul]

Ipv4+Labels is a good option...if both provider's are using Cisco/Alcatel/River stone (Not sure they have implemented send-label/Labeled unicast capability with Bgp)...and supporting draft-ietf-l2vpn-vpls-ldp

But if the either of the provider's are using Juniper which uses MBgp as the signalling protocol for VPLS...That's an issue

The first Inter-Provider Vpls using Mbgp was done between KT and Hutchison...

Now coming back to the issue...we can also do kind of VRF-VRF where the interconnect between the 2 can be part of the individual VFI instance of that AS.

But scalability will be an issue as u will have to create n number of sub-if's per VFI instances.

So u have broadcast/Arp frames being forwarded and learnt via the ASBR-ASBR Interconnect........The only issue can be trouleshooting across the AS's.

VPLS OAM is something which is still being debated...with VCCV being the prominent draft from Cisco...Juniper pushing lsp-ping/BFD and Alcatel having its own proprietary OAM(svc-ping)...

Hope the info is of some help.

Rgds

Aditya

[Harold Ritter]

Aditya,

Thanks for the excellent info. Just as a precision, even in the Juniper scenario, you would still need ipv4 + label in order to provide PE to PE reachibility between the two SPs.

[adityakaul]

Harold,

Pls dont get me wrong,Am not debating the merit of one implementation over the other...as far as i see both have their own advantages/disadvantges.

As far as the juniper scenario is concerned...there is no need for the Send-label/Labeled Unicast on the ASBR-ASBR link...as is the case with rfc2547 Option-A.

As u Referred the ipv4+label is the 2nd option and can also be used...

Incase there is a single or fewer Vpls instances...probably the first option makes sense to me from SP perspective..}:

Pls refer to the draft http://www.ietf.org/internet-drafts/draft-ietf-l2vpn-vpls-bgp-04.txt

3.3.1 a) VPLS-to-VPLS connections at the AS border routers

Thanks

Aditya

[Harold Ritter]

Aditya,

I see what you mean now. Labeled IPv4 is required only for 3.3.3 (option c). It is not required for 3.3.1 (option a) and 3.3.2 (option b).

Thanks for the clarification,

[nisha_kulkarni]

Hi Aditya...

That was very informative....Any more info on VCCV????

Regards,

NISHA

[Harold Ritter]

The following document has some information on VCCV:

http://www.cisco.com/univercd/cc/td/doc/product/software/ios120/120newft/120limit/120s/120s27/gslsppt.htm

Hope this helps,

[nisha_kulkarni]

thanks for the info....