Salon II RTG	pim	Protocol Independent Multicast WG *

PIM-DM - 
No one had reviewed the draft !!!
Review by the group is badly needed !!!!

Discussion about whether this should be experimental, 
informational or standards track.
Seemed to be no consensus.

Radia Pearlman
PIM Host extensions
the end nodes do PIM
intended to work for SSM

SSM now requires IGMPv3 support in the Host and the First Hop router.

PIM-HE - creates a unicast PIM Host Join message - destination of this 
packet is S Uses the IP router alert option on the IP header so that 
compliant routers can trap and process. If the router that receives this 
message is not first hop then the router Creates a tunnel fo the 
receiver

Process/demon is downloadable

Host-leave prune message needed as well

If first hop router receives, then just join the group. If not, then Have to 
worry about DOS attacks, so need to limit numbers of tunnels

Need to authenticate 

Q. How is this different from Ross Finlayson's automatic UDP encoding ?
A. Conceptually not very different - just one is UDP based and this one 
uses PIM.

Q. What if the tunnel connects two PIM domains ?
Dino F. - the difference is that the host just accepts multicast data  when 
it comes while a router does RPF checks. 

Mark Handley - I think that tunnels  between PIM clouds could create all 
sorts of problems and you might want to avoid this.

A. Solving the first mile problem is what we were focusing on here.

Mark Handley. I am worried about implosion problems. What if this gets 
really popular.
A. This allows some people to join, whereas before they couldn't get 
traffic at all.

Q. Dino F. - why make joins periodic ?
A. (to make them soft state)

Q. Liming W - Packets with Router alert may be blocked for, e.g., Cisco 
routers.
A.  I believe that this is not the case for all Cisco routers. 

A. Dino F.
If the a packet of a given protocol comes with a router alert, three 
things could happen
- - - if the protocol is unknown, forward
- - - if the protocol is PIM, gets sent to the PIM module, which will drop 
it.
- - - to do the right thing would require a new implementation, and old 
implementations would not do the right thing.

Q. Mark Handley Once the script kiddies discover router alerts, then 
everyone will stop forwarding them.

Bill Fenner - A useful thing would be to send packets with router alerts 
across real networks and see what happens,

Dino F. IGMPv2 and RSVP are the most common users of router alerts.

Beau Williamson - In my opinion, most of these tunneling ideas are 
something we can do technically, the real problems are getting it done from a 
business standpoint.

Tom P. Should this be a part of the working group charter ? Or MboneD
<Consensus seemed to be no, it should be in MBoneD>

Mark Handley
The PIM-SM spec has timed out. The spec is in good shape though.
IP Sec AH has been added. This is exactly what was done for IGMPv3 spec, and 
the IESG passed that.

Dave Thaler - I was just at the SEND WG and they have the exact same 
problem.

Mark Handley - The other spec is the BSR spec.
Tom P. Does the PIM spec depend on the BSR spec ?
Mark Handley - It is not totally clear if it does. Certainly 

That leaves the BiDir Spec
Isadore K. The BiDir spec is coming. It can maybe submitted at the same 
time Tom. P. So we need to do one more rev of that ?
Isadore K. - And also of the PIM spec.