RE: [PWE3] PWE Service interworking

["Jack Pugaczewski" <jtpugac@qwest.com>]

A carrier's perspective:

The existing customer based is a combination of the following Networking
Interworking options:
ATM-ATM, FR-FR, CE-CE, Ethernet-Ethernet

and Service Interworking Options:
ATM-FR, ATM-CES

A major purpose for moving to a converged MPLS (or PWE-3) network is to take
all of this functionality with as well a have the ability to introduce new
services (MPLS, IP,...).  This functionality must bring with it the OAM
fault and performance functionality that allows carriers to use the
combination of PE, CE and element management systems to perform fault
localization.

Specifications such as FRF.5 and FRF.8 are clearly defined and this same
approach should be used int the PWE3 space.

Respectfully,

Jack

PJMWBGJJREGTATALDBJHJHSLDHGSDWJAMY
 

F
> -----Original Message-----
> From: pwe3-admin@ietf.org [mailto:pwe3-admin@ietf.org]On Behalf Of Mark
> Seery
> Sent: Tuesday, June 03, 2003 11:01 PM
> To: pwe3@ietf.org
> Subject: Re: [PWE3] PWE Service interworking
>
>
> So having tried a general description, a slightly
> (not constructing access points etc.) treatment of
> this issue might look something like the following.
>
> Acronyms NIWF - network internetworking function and
> SIWF - Service interworking function are not acronyms
> used by any standards body (that I know of).
>
> fig.1 is essentially how I think of PW today.
>
> Network Interworking
> ====================
> fig.1
>
>  CE1         PE1         P         PE2       CE2
>         -----------            -----------
>         |   NIWF  |            |  NIWF   |
> ------  |---------|   ------   |---------|  ------
> | FR |--| FR | PW |---| PW |---| PW | FR |--| FR |
> ------  -----------   ------   -----------  ------
>
> Where FR could be FR, Ethernet, or ATM.
> In the ATM case, AAL5 would (typically) be
> encapsulated on to a PW, and no understanding of upper
> layer protocols would be required.
>
> Service Interworking
> ====================
> fig.2
>
>  CE1         PE1         P         PE2       CE2
>         -----------            -----------
>         |   SIWF  |            |         |
> ------  |---------|   ------   |         |  ------
> | FR |--| FR | PW |---| PW |---|   PW    |--| PW |
> ------  -----------   ------   -----------  ------
>
> The scenario of a PW going to a CE is unlikely today,
> of course, but shown here as a theoretical option.
>
> or
> fig.3
>
>  CE1         PE1         P         PE2       CE2
>         -----------            -----------
>         |   SIWF  |            |         |
> ------  |---------|   ------   |         |  ------
> | FR |--| FR | MP |---| MP |---|   MP    |--| MP |
> ------  -----------   ------   -----------  ------
>
> The scenario of a MPLS (MP) service going to a CE is
> more likely than that of a PW, but still not likely to
> be widespread in the near term
>
> or
> fig.4
>
>  CE1         PE1         P         PE2             CE2
>         -----------            -----------------
>         |   NIWF  |            |  NIWF | SIWF  |
> ------  |---------|   ------   |---------------|
> -----
> | FR |--| FR | PW |---| PW |---| PW | FR | ATM
> |--|ATM|
> ------  -----------   ------   -----------------
> -----
>
> In this scenario FR is encapsulated on to a PW at PE1
> and decapsulated off of a PW at PE2 and then service
> interworked to an ATM service. The ATM service may be
> going to a CE or to an ATM network (in which case the
> SIWF would be slightly different)
>
> or
> fig.5
>
>  CE1         PE1         P         PE2       CE2
>         -----------            -----------
>         |   SIWF  |            |  SIWF   |
> ------  |---------|   ------   |---------|  ------
> | FR |--| FR | PW |---| PW |---| PW | ATM|--| ATM|
> ------  -----------   ------   -----------  ------
>
> this seems simpler than some of the previous examples
> but might actually be quite hard and is where
> translation to from PW encaps would need to be pretty
> good (my guess).
>
> or
> fig.6
>
>  CE1       FR SW      ATM SW        PE1         P
>         -----------             -----------
>         |   SIWF  |             |NIWF/SIWF|
> ------  |---------|   -------   | --------|  ------
> | FR |--| FR | ATM|---| ATM |---| ATM | MP|--| MP |
> ------  -----------   -------   -----------  ------
>
> In this case FR is interworked with ATM, and RFC 1490
> with RFC 1483 at the FR SW. Then at the PE, ATM is
> network or service interworked with MP. In the case of
> routed RFC 1490/1483, an IP packet could be popped and
> encapsulated over MPLS, but there would still be OAM
> interworking between the ATM and MPLS functions.
>
> In the case of bridged RFC1490/1483, it may be
> possibly to interwork the ATM and MPLS functions and
> then interwork RFC1483 and PW.
>
> Just some ideas of scenarios we may be looking at in
> the future.
>
> Having thought about it, there is probably no getting
> by with just a casual discussion of this issue. So we
> either add it to the charter now, or delay it as seems
> to be the consensus (i.e. I have only heard one strong
> voice pushing it to the forefront).
>
> Mark
>
>
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