[rbridge] Use of 802.1ah Encaps
Gray, Eric
Eric.Gray at marconi.com
Tue Dec 12 12:59:11 PST 2006
Ali,
I am confused. What does it mean to say "at the UNI
you decide ... [and] you also decide at the UNI ..." if it
does not mean that the network operator determines these
things a priori and configures the equipment accordingly.
If there is a requirement for configuration - possibly
on an interface-by-interface basis - how is that plug and
play?
--
Eric
> -----Original Message-----
> From: Ali Sajassi (sajassi) [mailto:sajassi at cisco.com]
> Sent: Thursday, December 07, 2006 11:48 PM
> To: Gray, Eric; Don Fedyk; Joe Touch
> Cc: Developing a hybrid router/bridge.
> Subject: RE: [rbridge] Use of 802.1ah Encaps
>
>
>
> Gray,
>
> With respect to plug-and-play operation, it is similar to 802.1Q or
> 802.1ad operation; where, at the UNI you decide which interfaces belong
> to which VLANs in case of 802.1Q or which <interface, VLAN> pair belong
> to S-tag in case of 802.1ad (e.g., point-to-cloud config model). In case
> of 802.1ah, you also decide at the UNI which interfaces or which
> <interface, vlan> pair belong to which <B-tag, I-SID> pair. Again the
> model in 802.1ah is point-to-cloud model just like 802.1Q and 802.1ad
> and that's what makes it plug-and-play.
>
> -Ali
>
> > -----Original Message-----
> > From: Gray, Eric [mailto:Eric.Gray at marconi.com]
> > Sent: Thursday, December 07, 2006 5:38 AM
> > To: Don Fedyk; Joe Touch; Ali Sajassi (sajassi)
> > Cc: Developing a hybrid router/bridge.
> > Subject: RE: [rbridge] Use of 802.1ah Encaps
> >
> > Don,
> >
> > Thanks for doing this. As you can probably attest,
> > this is a non-trivial "digging" task to come up with this
> > level of detail. I am not sure why Joe asked for it, but now
> > that you have provided it, perhaps you can explain how values
> > would be derived for the B-TAG TCI/VID and I-TAG TCI/SID
> > fields if we'd like to deploy this technology in
> "plug-and-play" mode?
> >
> > --
> > Eric
> >
> > > -----Original Message-----
> > > From: Don Fedyk [mailto:dwfedyk at nortel.com]
> > > Sent: Thursday, December 07, 2006 8:29 AM
> > > To: Joe Touch; Ali Sajassi (sajassi)
> > > Cc: Gray, Eric; Developing a hybrid router/bridge.
> > > Subject: RE: [rbridge] Use of 802.1ah Encaps
> > >
> > > Hi
> > >
> > > This is the Provider Backbone Header Format reproduced from
> > one of the
> > > 802.1ah documents. When I said this is similar to the
> Trill header
> > > this is the version I mentioned. I converted to
> > textographics by hand
> > > so I hope I got it right. I put field designators in []
> inside the
> > > picture for fear they would get wrapped. The encapsulated
> > frame starts
> > > after the I-TAG I-SID.
> > >
> > >
> > > | 1 | 2 | 3 | 4
> > > |
> > >
> > +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
> > > -2 | |
> > |
> > > +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
> > +
> > > 2 | Backbone Destination Address
> > [B-DA] |
> > >
> > +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
> > > 6 | Backbone Source Address
> > [B-SA] |
> > > +
> > +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
> > > 10 | | .1ad Ethertype
> > [B-TAG] |
> > >
> > +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
> > > 14 | .1ad B-TAG TCI/VID | .1ah Ethertype [
> > ] |
> > > +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-[
> > I ]-+-+-+
> > > 18 | .1ah I-TAG TCI/SID [
> > - ] |
> > > +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-[
> > T ]-+-+-+
> > > 22 | Customer Destination Address [
> > A ] |
> > > + +-+-+-+-+-+-+-+-+-+-+-[
> > G ]-+-+-+
> > > 26 | | [
> > ] |
> > > +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ [
> > ] +
> > > 30 | Customer Source Address [
> > ] |
> > > +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-[
> > ]-+-+-+
> > > 34 | Encap Ethertype | [ ]
> > > +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
> > >
> > >
> > > .1ah I-TAG TCI
> > >
> > +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
> > > | P/DE |R1 |R2 | I-SID
> > |
> > >
> > +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
> > >
> > > P/DE 3 Bits Priority 1 bit Drop Eligible
> > > R1 Res1
> > > R2 Res2
> > >
> > > a) priority - This 3 bit field carries the customer
> > priority (I-PCP)
> > > associated with this frame. The provider network operates on the
> > > priority associated with the B-TAG.
> > >
> > > b) drop_eligible - This 1 bit field carries the customer drop
> > > eligibility
> > > (I-DEI) associated with this frame. The provider network
> > operates on
> > > the drop eligibility associated with the B-TAG.
> > >
> > > c) res1 - This 2 bit field is used for any future format
> > variations.
> > > The
> > > res2
> > > field is zero on transmit and is ignored on receipt.
> > >
> > > d) res2 - This 2 bit field is used for any future format
> > variations.
> > > The
> > > res1
> > > field is zero on transmit and if set on reception the frame is
> > > discarded.
> > >
> > > e) I-SID - This 24 bit field carries the service instance
> > identifier
> > > associated with this frame.
> > >
> > > f) encapsulated C-DA - This field carries the 48 bit
> > Destination MAC
> > > Address for an encapsulated Ethernet frame.
> > >
> > > g) encapsulated C-SA - This field carries the 48 bit Source MAC
> > > Address for an encapsulated Ethernet frame.
> > >
> > > Regards,
> > > Don
> > >
> > >
> > > > -----Original Message-----
> > > > From: Joe Touch [mailto:touch at ISI.EDU]
> > > > Sent: Wednesday, December 06, 2006 9:53 PM
> > > > To: Ali Sajassi (sajassi)
> > > > Cc: Fedyk, Don (BL60:1A00); Gray, Eric; Developing a hybrid
> > > > router/bridge.
> > > > Subject: Re: [rbridge] Use of 802.1ah Encaps
> > > >
> > > > I'd really rather someone just posted the header /
> fields, rather
> > > > than a large document in which that information is buried, if
> > > > possible ;-)
> > > >
> > > > Joe
> > > >
> > > > Ali Sajassi (sajassi) wrote:
> > > > >
> > > > >> Can you - or anyone with easy access to the specs -
> > > please post an
> > > > >> explicit description of 802.1ah header and fields?
> > > > >
> > > > > I will ask Tony (802.1 chair) to make avail to TRILL WG a
> > > > copy of .1ah.
> > > > >
> > > > > -Ali
> > > > >
> > > > >
> > > > >> Thanks,
> > > > >>
> > > > >> Joe
> > > > >>
> > > > >>
> > > >
> > > > --
> > > > ----------------------------------------
> > > > Joe Touch
> > > > Sr. Network Engineer, USAF TSAT Space Segment
> > > >
> > > >
> > >
> >
>
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