Re: HDLC, SDLC...
Another thing to keep in mind is that Cisco does not use a standard HDLC header. That's why PPP is recommended for interoperability with non-Cisco devices. Cisco doesn't take advantage of any of the reliability features of standard HDLC, and Cisco added a field to the header to identify the next layer up, such as IP, DDP, DECnet, etc. Cisco's HDLC has been discussed many times on this list, so check the archives for more details. Priscilla At 05:34 AM 9/6/00, michael champion wrote: >They are all based on the original work done by IBM for SDLC. SDLC uses a >complicated master-slave scheme that is not used in the other protocols. >However, the fields in all of the frames of the protocols mentioned were >basically derived from a special case of the SDLC protocol. > >Regards, >MLC > >perez claude-vincent <[EMAIL PROTECTED]> wrote in message >[EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > > Dear all, > > > > I am a little bit confused about the difference of > > framing between hdlc, sdlc, lapb, lapd, llc2. > > > > Can someone help me? > > > > Thank you, cvp. > > > > > > > > __ > > Do You Yahoo!? > > Yahoo! Mail - Free email you can access from anywhere! > > http://mail.yahoo.com/ > > > > ___ > > UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html > > FAQ, list archives, and subscription info: http://www.groupstudy.com > > Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] > > > > >___ >UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html >FAQ, list archives, and subscription info: http://www.groupstudy.com >Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] Priscilla Oppenheimer http://www.priscilla.com ___ UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html FAQ, list archives, and subscription info: http://www.groupstudy.com Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: HDLC, SDLC...
These are all Layer 2 protocols. This site has some very good explanations of the differences. http://www.sangoma.com/tutorial.htm LLC2 = IEEE 802.2 Logical Link Control Type 2. Used by SNA and NetBIOS on a LAN. Frame Format: http://www.protocols.com/pbook/lan.htm#LLC LAPD = Access protocol on ISDN D channel. Ensures error free transmission. Frame Format: http://www.protocols.com/pbook/isdn.htm#LAPD HDLC = Sets the framing structure for synchronous communications and is responsible for the error-free movement of data between network nodes. There are two different implementations of HDLC, HDLC NRM (also known as SDLC) and HDLC LAPB. NRM is MAster/slave. LAPB is peer-to-peer. Frame Format: http://www.protocols.com/pbook/x25.htm#HDLC LAPB = CCITT adaptation of HDLC. Used to carry X.25 commands and control frames. Supports full-duplex operations and is peer-to-peer (neither end plays the role of master on a permanent basis). Frame Format: http://www.protocols.com/pbook/x25.htm#LAPB SDLC = Developed by IBM. Performes the layer 2 functions of the SNA hierarchy. SDLC is virtually identical to HDLC Normal Response Mode and was developed to replace the Bisynchronous protocol for WAN connections between IBM equipment. Primarily half-duplex but is capable of supporting full-duplex. Not a peer-to-peer protocol like HDLC/LAPB, X.25, and Frame-Relay. Frame Format: http://www.protocols.com/pbook/sna.htm#SDLC Nope this helps, Karen E Young Network Engineer ELF Technologies, Inc [EMAIL PROTECTED] perez claude-vincent To: [EMAIL PROTECTED] Subject: HDLC, SDLC... Sent by: nobody@groupstud y.com 09/05/2000 10:46 PM Please respond to perez claude-vincent Dear all, I am a little bit confused about the difference of framing between hdlc, sdlc, lapb, lapd, llc2. Can someone help me? Thank you, cvp. __ Do You Yahoo!? Yahoo! Mail - Free email you can access from anywhere! http://mail.yahoo.com/ ___ UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html FAQ, list archives, and subscription info: http://www.groupstudy.com Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] ___ UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html FAQ, list archives, and subscription info: http://www.groupstudy.com Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: HDLC, SDLC...
They are all based on the original work done by IBM for SDLC. SDLC uses a complicated master-slave scheme that is not used in the other protocols. However, the fields in all of the frames of the protocols mentioned were basically derived from a special case of the SDLC protocol. Regards, MLC perez claude-vincent <[EMAIL PROTECTED]> wrote in message [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > Dear all, > > I am a little bit confused about the difference of > framing between hdlc, sdlc, lapb, lapd, llc2. > > Can someone help me? > > Thank you, cvp. > > > > __ > Do You Yahoo!? > Yahoo! Mail - Free email you can access from anywhere! > http://mail.yahoo.com/ > > ___ > UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html > FAQ, list archives, and subscription info: http://www.groupstudy.com > Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] > ___ UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html FAQ, list archives, and subscription info: http://www.groupstudy.com Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
RE: HDLC, SDLC...
I can explain the first three protocols namely hdlc, sdlc, lapb First of all they are all WAN protocols, which is layer 2 protocol for communicating across a WAN link, which protocol to use depends on two factors the WAN technology that you use and the communicating equipment HDLC stands for High-level Data link Control which is the default encapsulation type on point-to-point , dedicated links. It is used typically when communicating bet two CISCO devices. It is a bit oriented synchronous data link layer protocol.HDLC specifies a data encapsulation method on synchronous serial links using frame characters and checksums. If communicating with a non-Cisco device , synchronous PPP is a more viable option SDLC stands for Serial Data Link Control use mainly for SNA networks and lapb Link Access Procedure, Balanced is for X.25 links Jason -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of perez claude-vincent Sent: Wednesday, September 06, 2000 1:46 PM To: [EMAIL PROTECTED] Subject: HDLC, SDLC... Dear all, I am a little bit confused about the difference of framing between hdlc, sdlc, lapb, lapd, llc2. Can someone help me? Thank you, cvp. __ Do You Yahoo!? Yahoo! Mail - Free email you can access from anywhere! http://mail.yahoo.com/ ___ UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html FAQ, list archives, and subscription info: http://www.groupstudy.com Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] ___ UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html FAQ, list archives, and subscription info: http://www.groupstudy.com Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
HDLC, SDLC...
Dear all, I am a little bit confused about the difference of framing between hdlc, sdlc, lapb, lapd, llc2. Can someone help me? Thank you, cvp. __ Do You Yahoo!? Yahoo! Mail - Free email you can access from anywhere! http://mail.yahoo.com/ ___ UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html FAQ, list archives, and subscription info: http://www.groupstudy.com Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
