Re: MPLS / Switching Method on Non Cisco Devices

Ahh..a reply finally ;-) .. Thanks Carlos .. however, my query is more
oriented towards the switching method utilized for MPLS in Non-Cisco routers
(Juniper etc .) rather than on the WAN encapsulation type or device
used..for example a cisco router would build a LFIB and LIB using CEF , but
since non-cisco routers do not use CEF, do they build the same data
structures and if their packet switching method is similar to CEF which
builds FIB and adjacency tables..

Thanks for your reply again,

Ravi

On Wed, Jan 13, 2010 at 1:18 PM, Carlos G Mendioroz <tron_at_huapi.ba.ar>wrote:

> Well, it seems that conceptual things are not very attractive as topics.
> (just some pepper to the mix :)
>
> CEF is cisco's way to do it, but in general, MPLS is hardware friendly
> no matter what way you do it, because it has a fixed size fixed position
> small label that can be used to determine where the frame/packet should
> go in constant time.
> ATM has a even better constant size frame (cell), but at the cost of
> forcing SAR (segmentation and reassembly) on upper stack.
> FR/ATM switches usually specify how many *bits* they can read in
> hardware to switch traffic, I guess nowadays MPLS-able switches should
> do the whole label.
>
> As to who decides the label, there are two alternatives to when it is
> done but always the link receiver is the one. Frame mode allows for it
> to be determined up front, usually when the FEC is created.
> Cell mode does it on-demand, to economize the number of circuits
> that are mapped to them. (label mapped to VPI/VCI)
>
> My understanding at least, hope it helps.
> -Carlos
>
> Ravi Singh @ 6/01/2010 8:52 -0300 dixit:
> > Greetings Everyone ,
> >
> > From all the MPLS material I have read, I understand the dependency of
> CEF
> > on MPLS . However, just out of interest, I would like to know what
> switching
> > methods do the non-Cisco equipment utilize for MPLS functioning. I tried
> > finding the information on the web but could not get any valuable info.
> > I know nothing about Juniper or any other non-cisco equipment for that
> > matter but I am just curious to know how different is the switching
> > behaviour in these devices when compared to Cisco. So I am really not
> > looking for detailed technical stuff but just a clarity on who takes the
> > care of the label assignment in such a case.
> >
> > Cheers,
> > Ravi
> >
> >
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>
> --
> Carlos G Mendioroz <tron_at_huapi.ba.ar> LW7 EQI Argentina

Blogs and organic groups at http://www.ccie.net
Received on Wed Jan 13 2010 - 13:37:16 ART