Subject: Re: [mpls] Scalability with regards to draft-chen-mpls-mldp-deployment-via-p2p-tunnels-00

From: Lizhong Jin <[email-masked]>
Date: Sun, 29 Apr 2012 00:33:19 +0800

Hi Emily,
The most concern from me is, since you need to upgrade the non-mLDP node to
support the feature in the draft (tunnel through feature), why not upgrade
the node to support mLDP directly?
What's more, since as you said below, the heavy duty node needs to upgrade
with mLDP. How do you know it is a heavy duty node or not? The receiving
nodes would change as the time goes. Maybe it is reasonable to consider
every node to be potential heavy node, and upgrade every node with mLDP. I
doubt if there would be requirement that part of nodes require to upgrade
with mLDP, and part of nodes require to upgrade with the feature in the
draft?

Regards
Lizhong

Send from my iPad

> ----------------------------------------------------------------------
>
> Message: 1
> Date: Mon, 2 Apr 2012 20:43:58 +0000
> From: "Chenying (Emily)" <[email-masked]>
> To: IJsbrand Wijnands <[email-masked]>
> Cc: "[email-masked]" <[email-masked]>
> Subject: Re: [mpls] Scalability with regards to
>        draft-chen-mpls-mldp-deployment-via-p2p-tunnels-00
> Message-ID:
>        <
[email-masked]>
>
> Content-Type: text/plain; charset="us-ascii"
>
> Dear Ice,
>
> Thanks for your comments. IMO, the mldp-via-p2p-tunnel and
mldp-node-protection mechanisms are under different situations. The
following is my 2 cents, please see whether this make sense to you. Thanks.
>
> The scalability issue would exist only when N node has a large number of
downstream routers. In mLDP deployment scenario, if users want to upgrade
the network into a mLDP capable one, such 'heavy-duty' N node should be the
first priority for upgrade, because it really need packet duplication
functionality. Once the N node is upgraded, then t-ldp is not needed, and
there is no scalability issue at all. But in mldp-node-protection scenario,
such 'heavy-duty' N node should be the first priority for node protection,
because it is really important for the multicast tree. Then the t-ldp
sessions are always needed, and the scalability issue will always exist.
This is why I think the mldp-via-p2p-tunnel and mldp-node-protection
mechanisms are under different situations.
>
>
> Best regards,
> Emily Chen
>
> -----Original Message-----
> From: IJsbrand Wijnands [mailto:[email-masked]]
> Sent: Monday, April 02, 2012 12:34 AM
> To: Chenying (Emily); Quintin zhao
> Cc: [email-masked]
> Subject: Scalability with regards to
draft-chen-mpls-mldp-deployment-via-p2p-tunnels-00
>
> Dear Emily & Quintin,
>
> The solution in this draft requires a mLDP router upstream of the
non-mLDP router to do the packet forwarding and replication. The receiver
interest is signaled to the upstream router via tLDP sessions. The upstream
router will end up with the number of tLDP session to all the of the
receivers downstream of the non-mLDP router, and will have to replicate the
multicast packets over P2P LSPs to them.je
>
> This has exactly the same tLDP scale considerations as discussed in the
context of draft-wijnands-mpls-mldp-node-protection-00, yet for mLDP node
protection it seems to be a concern for you?
>
> Thx,
>
> Ice.
>
> BTW, we already have had a fair bit of discussion on the list Oct 2011
regarding the other concerns for this draft.
>
>
> ------------------------------