Transcript 11/756r0: IP address assignment in FIA (Robert Moskowitz, Verizon Business)

May 2011
doc.: IEEE 802.11-11/0756r0
IP Address Assignment in FIA
Date: 2011-05-10
Authors:
Name
Company
Address
Robert
Moskowitz
Verizon Business
15210 Sutherland, Oak Park,
+1-248-219-2059
MI 48237, USA
Submission
Phone
Slide 1
email
[email protected]
Robert Moskowitz, Verizon
May 2011
doc.: IEEE 802.11-11/0756r0
Abstract
This document presents an approach to assigning IP addresses during
the ASSOCIATION phase in 802.11 link establishment.
Submission
Slide 2
Robert Moskowitz, Verizon
May 2011
doc.: IEEE 802.11-11/0756r0
Agenda
• Problem statement
• Solution overview
• Conclusions
Submission
Slide 3
Robert Moskowitz, Verizon
May 2011
doc.: IEEE 802.11-11/0756r0
Problem Statement
• Why Fast Address Assignment?
– STA always 'knows' at link establishment if an IP address is needed
for the link, and for which IP version(s).
– IP address assignment is a MAC supported function.
• Ultimate goal:
– Can we shorten the time for address assignment?
Submission
Slide 4
Robert Moskowitz, Verizon
May 2011
doc.: IEEE 802.11-11/0756r0
Problem Statement
• IP addressing Methodologies
– DHCP – v4 and v6
• AP as DHCP server
• AP as MAC bridge with DHCP server 'behind it'
• AP as DHCP relay
– IPv6 Neighbor Discovery Router Announcements
• AP as Router
• AP as MAC bridge with RA server 'behind it'
• AP acting as RA 'relay'
Submission
Slide 5
Robert Moskowitz, Verizon
May 2011
doc.: IEEE 802.11-11/0756r0
Problem Statement
• AP as MAC bridge will NOT allow for IP addressing
during ASSOCIATE
– AP MUST have some direct support for DHCP or IPv6 RA
• RA 'relay' is a 'simple' caching mechanism
– DHCP relay service MAY result in ASSOCIATION RESPONSE
timing challenges
• Are there any timing considerations for the
ASSOCIATE RESPONSE?
– Not in 802.11, but claims there are in WiFi certification (5 ms)
– If address is not available within time window, ASSOCIATE with
'no address yet'. STA then uses 'standard' datagram method?
• What to do with DHCP response when it finally
comes?
Submission
Slide 6
Robert Moskowitz, Verizon
May 2011
doc.: IEEE 802.11-11/0756r0
Problem Statement
• To get an IP address as part of ASSOCIATE, the STA
MUST ask for it in the REQUEST
• Should ASSOCIATE RESPONSE timing be loosened if
REQUEST contained a request for an IP address?
– If so, how much time is 'reasonable'?
Submission
Slide 7
Robert Moskowitz, Verizon
May 2011
doc.: IEEE 802.11-11/0756r0
Conclusions
• It is possible, and in many cases practical, to deliver an
IP address during ASSOCIATE
• This is a clear layer violation, but can save time for
Link Setup
Thank you!
Submission
Slide 8
Robert Moskowitz, Verizon