Subject: MPLS topology questions

From: Pyda Srisuresh <[email-masked]>
Date: Tue, 7 Dec 1999 16:33:11 -0800 (PST)

Folks,

I have a few rudimentary questions on MPLS. Would appreciate any 
responses from you knowledged folks out there. Thanks.

    1. How wide is the MPLS network deployment? Are the MPLS networks 
       currently in deployment being used predominantly for VPNs (or) 
       for some other purpose?

    2. I believe, MPLS nodes operate only on high speed WAN inter-links.
       (OC-3, OC-12, OC-48 etc.). Is this accurate (or) are there LAN and
       other low-speed links as well supported?

    3. Does every node in an MPLS network have to be a router running 
       MPLS protocol (on top of some IGP)? If so, is there no room for 
       end-hosts? For example, does an SNMP application node used to 
       monitor the network also have to be attached on an OC-x link 
       and be talking MPLS label switching protocol with other nodes 
       in the network?

Thanks.

regards,
suresh

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---

From: Pyda Srisuresh <[email-masked]>
Date: Tue, 7 Dec 1999 17:52:38 -0800 (PST)

Thanks for the response. Please see additional comments below.

--- Shahram Davari <[email-masked]> wrote:
> Hi,
> 
> Below are some answers:
> 
> -Shahram
> 
> > -----Original Message-----
> > From: Pyda Srisuresh [mailto:[email-masked]]
> > Sent: Tuesday, December 07, 1999 4:33 PM
> > To: [email-masked]; [email-masked]
> > Cc: [email-masked]
> > Subject: MPLS topology questions
> > 
> > 
> > 
> > Folks,
> > 
> As far as I know MPLS is currently mostly used for Traffic Engineering.

Specifically, are there typically multiple interconnected LSPs in the 
network between a pair of ingress and egress points (or) is that a
single LSP between every pair of ingress and egress nodes?

By traffic engineering, I assume, you are refering to LSPs with fixed
bandwidth. Right?

> Yes. MPLS is speed and media independent, so you can use it almost anywhere.
> 

Are there any deployments that use MPLS for traffic engineering, 
with LANs and low-speed WAN links in the network? Is this a common
scenario to have LANs in an MPLS network?

If so, is the bandwidth management on LANs done through software (such 
as fair queuing)?

> No, if some routers in the network don't support MPLS, they won't be
> participating in MPLS path establishment. Also it is a network designer's
> choice to extend the MPLS all the way to the host or just use it in the core
> of the network. Besides you can have non-MPLS traffic also in an MPLS
> network.
> 

I believe, what you are saying is that end hosts can be within an MPLS 
network (say, on a LAN), provided they talk MPLS. Do you know of any host
vendors (such as SUN, HP and Microsoft) that support MPLS on end hosts? 
Specifically, is an SNMP management station allowed to talk IP to the
LSRs in the MPLS network?

Thanks.

regards,
suresh

---

From: Shahram Davari <[email-masked]>
Date: Tue, 7 Dec 1999 18:19:33 -0800

Hi,

Please see comments:

> Sent: Tuesday, December 07, 1999 5:53 PM
> To: Shahram Davari; [email-masked]; [email-masked]
> Subject: RE: MPLS topology questions
> 
> 
> 

Both are possible. You can have one single end-to-end LSP or you can have
multiple spliced LSPs, or even both (in case of label stacking). One of the
attributes of a Traffic Engineered LSPs (trunk) are traffic attributes
(peak-rate, average-rate and burst-size).

> If so, is the bandwidth management on LANs done through 

Theoretically speaking MPLS can be implemented in LANs. However, I can't
comment on how useful this is.

> LSRs in the MPLS network?

Yes correct. Sorry I don't know of host vendors. As I told you can still
talk IP (non-MPLS) in an MPLS network.