802.1H Revision Project
Kevin Nolish
Michael Wright
802.1H - Background
• 802.1H is a recommended practice that
concerns bridging interconnected LANs
where a mixture of 802.3 and Ethernet
v2.0 traffic is present. It also addresses
bridging between LANs with different
underlying data links.
– Originally Ethernet and Token Ring or FDDI
– Today the biggest usage seems to be in
802.11
802.1H PAR Highlights
• Need for the project
– 802.1H is in need of updating to reflect
developments in bridging since publication in
1997 and to correct inaccuracies in the text
resulting from changes in other standards.
• PAR Approval Date : 15 Sep 2006
• PAR Expiration Date : 31 Dec 2010
• Original Submission Dates
– Enter Sponser Ballot : 7 2008
– RevCom Submittal : 7 2009
Editor’s Plans
• Update the Service Model
• Remove Older Technologies
– 802.5
– FDDI ?
• Add new technologies
– 802.11 makes use of RFC1042 and 802.1H as
configuration options.
• Clause 6.1.4 of 802.11 2007 MSDU format
• Annex M Integration function
– Recommends the use of 802.1h
• Add MIB items
• Add protocol definition table
PB and PBB bridging
• What are the implications for technologies
that stack tags?
– Should 802.1H address such technologies?
– Do we have to convert just the outermost tag,
or do we have to deal with the entire tag
stack?
– Presumably VLAN tags behind an I-TAG don’t
matter.
– Does 802.1H apply to S, B, or I components?
Project Schedule
• Limit the scope of the project to updating
the document to those 802 technologies
that use 802.1h
– Is this satisfactory with 802.1?
• We will need input from 802.11 and any
other dot group that uses 802.1h
Next Steps
• Editors active solicit feedback and
welcome any input
• Editors will produce a draft for task group
ballot
• Need active participation of someone from
802.11 since their standard does make
use of 802.1h
Backup Slides
802.11 Issues
• 802.11 Classifier Type 2 has a VLAN ID
– Does this require a similar kind of conversion going
between an 802.3 and 802.11 interface?
• Annex M.3 of 802.11 calls out bridging of VLAN
tagged MSDUs between 802.3 and 802.11
LANs.
– Investigate This
• Is the WLAN integration service a replacement
for bridging? If so 802.1H may not apply.
SNAP Encoded VLAN Tags
• Apparently on some LANs other than 802.3, the
VLAN tag must be carried by a SNAP encoding.
– DSAP-AA SSAP-AA CTL-3
– Protocol ID 00-00-00-81-00
– Followed by VLAN TAG
What are these technologies? Are they still relevant?
Do we have to do this LLC encoding? Are LLC
encoded VLAN tags acceptable on 802.3, thus buying
into the rfc 1042 problem, or can we ALWAYS cut out
the LLC/SNAP portion of the tag when going to 802.3
from something else?
802.15
• The major 802.15 standard, 802.15.1
doesn’t mention VLANs.
• There are other standards regarding
interworking with wireless networks, but I
think that 802.15 will not be a problem
child.
• Upon reflection, VLANs in a Personal Area
Network are a little odd.
802.16
• 802.16 needs to be investigated. Section
5.2.5 refers to 802.1Q tagged frames.
• This is probably OK as this seems to be
referring to carrying 802.1Q tagged frames
as opposed to 802.16 having a VLAN
concept of its own requiring an LLC/SNAP
encoded Vlan TAG.
Diagram Issues
• What, exactly, are the semantics of the
ISO/IEC service model diagrams?
– Does the circle represent a lan or an
interconnection?
– Would these be better off if replaced with a
baggy pants style diagram?
• The editors realize that, generally,
illustrating frames is considered a bad idea
in 802.1, but it seems to be central to
802.1H.