Hi Jari,
This looks good to me. Margaret At 06:34 PM 5/30/02 , Jari Arkko wrote: >Follow-up to my own e-mail, after some off-line discussions. >Here's an updated suggestion for the address resolution etc part: > > > 2.4 RFC2461 - Neighbor Discovery for IPv6 > > Neighbor Discovery is described in [RFC-2461]. This > specification is a mandatory part of IPv6. > > 2.4.1 Neighbor Discovery in 3GPP Networks > > Hosts must support Neighbour Solicitation and > Advertisement messages. > > In GPRS and UMTS networks, some Neighbor Discovery > messaging can be unnecessary in certain cases. > GPRS and UMTS links resemble a point-to-point link; > hence, the host's only neighbor on the cellular > link is the defaul router that is already known > through Router Discovery. There are no link layer > > addresses. Therefore, address resolution and next-hop > determination are not needed. > >Secondly, about alternative 1 for the advice to give for NUD. > >I've been asked to provide more details about the specific >protocol layers, whether the tunnel and the payload stacks >are the same etc. We'll send an e-mail about this tomorrow. > >Finally, for alternative 3 I have some updated text regarding >what kind of advice to give: > > > The host must support neighbour unreachability > detection as specified in [RFC-2461]. > > In GPRS and UMTS networks, it is very desireable to > conserve bandwidth. Therefore, hosts stacks used in > these environments should include a mechanism > in upper layer protocols to provide > reachability confirmation when two-way IP layer > reachability can be confirmed (see RFC-2461, > Section 7.3.1). These confirmations will allow the > suppression of most NUD-related messages. > > Host TCP implementation should provide > reachability confirmation in the manner > > explained in RFC 2461, Section 7.3.1. > > > The use of UDP for many purposes in 3GPP > networks poses a problem for providing this > reachability confirmation. UDP itself is > unable provide such confirmation. Instead, > applications running over UDP should provide > the confirmation where possible. In particular, > when UDP is used for transporting RTP, the RTCP > protocol feedback should be used as a basis for > the reachability confirmation. If an RTCP > > packet is received with a reception report block > indicating some packets have gone through, then packets > are reaching the peer. If they have reached the > peer, they have also reached the neighbour. > > When UDP is used for transporting SIP, responses to > > SIP requests should be used as the confirmation that > > packets sent to the peer are reaching it. > The receipt of new non-retransmitted requests within > a SIP dialog should be used as a confirmation that > previous responses have reached the peer. > >Jari -------------------------------------------------------------------- IETF IPng Working Group Mailing List IPng Home Page: http://playground.sun.com/ipng FTP archive: ftp://playground.sun.com/pub/ipng Direct all administrative requests to [EMAIL PROTECTED] --------------------------------------------------------------------
