That's 40% right. SQL, NFS, and XWindows are application-layer protocols.
RPC and NetBIOS are session-layer protocols. We often have discussions about which books are best. Todd Lammle books can teach you basic router configuration. They are often wrong where protocol behavior is concerned. A better reference for learning about OSI is the OSI paper by Howard Berkowitz at http://www.certificationzone.com. Priscilla At 11:32 PM 12/7/01, anil wrote: > >The session layer is an elusive beast that is not implemented much >Yes, I checked it out.. >Session layer protocols include: >SQL, NFS, RPC, NetBios, Xwindows are examples of session layer protocols. >Page 9 of CCNA 2nd Edition study guide Todd Lammle > >-Anil > > > > >-----Original Message----- >From: anil [mailto:[EMAIL PROTECTED]] >Sent: Friday, December 07, 2001 11:17 PM >To: Priscilla Oppenheimer; [EMAIL PROTECTED] >Subject: RE: Does session layer protocol use IP address ? [7:28378] > > > >The session layer is an elusive beast that is not implemented much >Wait a sec, I thought SQL, NFS and netbios were session layer protocols? >Someone please correct me. >-Anil > > >-----Original Message----- >From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of >Priscilla Oppenheimer >Sent: Friday, December 07, 2001 9:55 PM >To: [EMAIL PROTECTED] >Subject: Re: Does session layer protocol use IP address ? [7:28378] > > >At 02:59 AM 12/7/01, mlh wrote: > >Hi, there, > > > >I read Todd Lammle's CCNA2.0 study guide and found this sentence: "Remember > >that none of the upper > >layers know anything about networking or network addresses." I am wondering > >if the session layer doesn't > >use network address, how can it establish a dialogue with other session > >layer in other host? > >I would probably disagree with Todd's statement, although it's taken out of >context and you haven't given us enough information to say that the >statement is definitely "wrong." > >However, try to picture the numerous OSI pictures you have seen. Most of >them show horizontal lines between a layer on one host talking to the same >layer on another host. So the session layer talks to the session layer on >the other host. That's probably what Todd was getting at. > >However, the pictures also show vertical lines. A layer calls on a layer >below to provide services. Each layer offers services to layers above it. > >The session layer is an elusive beast that is not implemented much. But one >example might help. NetBIOS is a session layer. On a Windows client, when >you access a Server Message Block (SMB) server, NetBIOS has the job of >setting up a session with the server. Before it can do that, however, it >must find the address of the server. If it's a modern Windows network, then >SMB and NetBIOS are probably running above TCP/IP and UDP/IP. So NetBIOS >sends a DNS or WINS query to find the IP address of the named server. It >then sets up a NetBIOS session with the server. Actually, first, the client >sets up a TCP connection. TCP has port numbers. The client sends to the >well-known TCP port for NetBIOS session (139) and use an ephemeral port on >its side. These port numbers could be considered "addresses" at the >transport layer. > >Anyway, back to the question. The statement is at best over-simplified. I >recommend you get yourself a sniffer and watch what really happens between >layers. (Ethereal is free by the way.) > >Priscilla > > > > >Thank you for your time. > > > >mlh >________________________ > >Priscilla Oppenheimer >http://www.priscilla.com ________________________ Priscilla Oppenheimer http://www.priscilla.com Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=28503&t=28378 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
