[e-mail]

1
BURP Requirements behind draft-ietf-dhc-aaa-ra-00
.txt

• George Tsirtsis G.Tsirtsis_at_flarion.com

2
What is the point of this?

• PPP for on-demand user/terminal connectivity
• Dial-up users
• Cable, DSL and wireless introduce always-on
  connectivity
• But users also move around and between terminals
• DHCP PPP Internet Access model is needed
• To allow any user to access the Internet from any
  terminal

3
PPP Internet Access Model
3.Internet Access
2.AAA
AAA
Access Router

• 2.AAA
• User authentication but also..
• users profile
• accounting requirements
• multicast capability,
• -diffServ markings etc

1.PPP
4
Proposed DHCP Internet Access Model
3.DHCP Relay
4.Internet Access
2.AAA
AAA
3.AAA User authentication but also users
profile as in PPP
Access Router Relay Agent
1.DHCP
5
Why full AAA instead of just registration?

• Full AAA provides a superset of registration
• And thus can do registration only if required
• But can also do Access Control, accounting etc
• Registration is not useful without policing and
  potentially accounting
• AAA provides all the above
• If the goal is to find alternative to PPP then
  that is the only choice
• Otherwise we are going to lose functionality in
  the process

6
Why use the Access Router

• All As in AAA collocate with AR
• So, AAA is done ones!
• So it is simpler distribution stops at AR level
• Firewalling, accounting and profiling happens at
  the same point
• AAA client is in the first IP Router (the edge)
• AAA include IP profile which has to be installed
  at the AR
• AAA is triggered at IP layer (or sub-IP but L2
  independent)
• So it can apply to all link layers
• So existing link layers do not have to change
• So future link layers do not have to think about
  it
• So we can use multiple link layer hops between
  end node and AR

7
Why DHCP? And why not

• End nodes need IP address to operate
• DHCP provides IP addresses
• Maps them to Link Layer addresses
• But even if they do notthey need other config.
  (DNS, etc)
• DHCP already implements RAs
• RAs look like other side of AAA clients
• They are positioned in the right place (AR)
• Most nodes support DHCP
• Why not DHCP?
• Well established protocol widely deployed I.e.
  difficult to change
• It is better to do one thing and do it right
• Some IPv6 nodes may not support DHCPv6 (more
  complex than dhcpv4, plug and play available)

8
A new protocol?maybe.

• A new protocol would allow modular support of
  services (autoconfig, dhcp, authentication, etc)
• But, lets keep the good things about dhcp-aaa
• BURP between end node and AR
• BURP triggers (or is integrated with) AAA client
  at AR
• Keep in mind what functionality PPP
  provides.anything less may not be good enough.