Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!cs.utexas.edu!uunet!pdn!larry From: larry@pdn.paradyne.com (Larry Swift) Newsgroups: comp.dcom.lans Subject: Re: What services does X.25 provide? Keywords: x.25, services, login, e-mail, file transfer, IPC Message-ID: <6624@pdn.paradyne.com> Date: 2 Oct 89 12:43:54 GMT References: <796@maxim.erbe.se> <3279@wasatch.utah.edu> <522@wet.UUCP> <1989Sep18.020822.16329@cit5.cit.oz> <22877@cos.com> Sender: usenet@pdn.paradyne.com Reply-To: larry@pdn.paradyne.com (Larry Swift) Organization: AT&T Paradyne, Largo, Florida Lines: 19 In article <22877@cos.com> howard@cos.com (Howard C. Berkowitz) writes: >The second is one way to provide the Connectionless Network Service >(CLNS); it uses X.25 to provide a technology-specific interface >to a packet-switching network, but the service interface shown to Transport >is connectionless, based on the OSI Internet Protocol (ISO 8473). This description seems to be implying a reason for this interface, but if so, it escapes me. Can you provide some background as to why network designers might want a CNLS interface over an inherently connection-oriented network layer? If the Layer 3 path traversed multiple subnets with an unreliable segment such as X.25-Ethernet-X.25, is the CNLS interface to Layer 4 no less viable than the CONS? Is it simply easier to use? What else? Larry Swift larry@pdn.paradyne.com AT&T Paradyne, LG-132 Phone: (813) 530-8605 8545 - 126th Avenue, North Largo, FL, 34649-2826 She's old and she's creaky, but she holds!