I have her book (second edition) and I think she agrees with John. She says this about the LES:
LES: The node that keeps the mapping from MAC address to ATM address. A LEC registers its own (MAC, ATM) address with the LES and finds out the ATM address of other LECs by asking the LES. A LES supports one ELAN. A LES maintains a point-to-multipoint VC from itself to all LECs in the ELAN. (She doesn't say that the LES sits in the middle between LEC conversations). On the next page, she gets into the rest of the story and says "the LEC asks the LES for the ATM address corresponding to layer 2 address D. When it finds out (from the LES), the LEC establishes a VC to that ATM address, and future packets for D are forwarded over that VC. To send a multicast (or broadcast), the LEC must find the ATM address of the BUS. It finds that by asking the LES for the ATM address of FFFFFFFFFFFF. The LEC then establishes a VC to the BUS.... When a LEC sends it a packet to multicast, the BUS retransmits the packet onto the point-to-multipoint VC. In other words, Radia agrees with all the other experts. Not a big surprise there! ;-) Priscilla At 10:36 AM 12/13/01, John Neiberger wrote: >I don't have her book available so I can't comment directly on the >content. However, read through the following document: > >http://www.cisco.com/univercd/cc/td/doc/product/software/ios120/12cgcr/switch_c/xcprt7/xcovlane.htm > > >What out for line wrap on that one. > >You can see that once the LEC has resolved the address of the remote >LEC to which it wants to communicate, a bi-directional data direct VCC >is setup and all data flow *directly* between the two LANE clients. The >LES gets involved when a LEC wants to join an ELAN and when address >resolution is required. Beyond that it doesn't do much. > >Regards, >John > > >>> "nettable_walker" 12/13/01 7:14:12 AM > >>> >12/13/2001 8:15am Thursday > >I am really stumped --- Radia Perlman's book seem to say the oposite of >what >you are saying --- page 289 > > > HELP !!! > > > >""John Neiberger"" wrote in message >[EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > > No. Once SVCs are setup between the LECs, traffic flows > > directly between them without the use of the LES. The LES > > facilitates the initial connections but is not involved in the > > traffic flow after the end-to-end SVC is in place. > > > > I think. :-) You may want to double check that answer. It's > > been a while since I've even thought about LANE. > > > > Regards, > > John > > > > ---- On Wed, 12 Dec 2001, nettable_walker > > ([EMAIL PROTECTED]) wrote: > > > > > 12/12/2001 10:45pm Wednesday > > > > > > Professionals, > > > > > > Is the LES a transit point for all traffic between LEC's ? > > > > > > Thanks, > > > > > > Richard > > > > > > // > > [EMAIL PROTECTED] > > > > > > > > > > > > ________________________________________________ > > Get your own "800" number > > Voicemail, fax, email, and a lot more > > http://www.ureach.com/reg/tag ________________________ Priscilla Oppenheimer http://www.priscilla.com Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=29113&t=29113 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
