RE: x.25 question help
The X.25 standard does have optional throughput classes, although I've never seen much attention paid to them in practice. IIRC, they go up to 2MB or 4 MB or so. They aren't, however, hard limits. I've certainly seen X.25 running on E1's. LAP-B unquestionably is used at higher speeds on satellite links. As an attempt to unify the CCITT and LAN worlds, there are ISO standards for running the OSI Connection-Oriented Network Service over LLC, and for LLC over CONS. ISO 8881 and 8880, from memory, although I might have them reversed. The UK's JANET network certainly used these. So, X.25 certainly has been run over Ethernet. I can't think of an inherent reason that there would be a hard bandwidth limit. Last I looked, X.25 was in the process switching path, so processor load would become a limit. I seem to remember that there was a performance cutoff of around 8 9.6Kbps heavily loaded X.25 links on an old 4000 router, which has a 68040 derated from the one on the 7000. >First up, I would like to point out that I have NO hands-on experience of >X.25 - this is considering the question from the theoretical Cisco point of >view, which doesn't necessarily have anything to do with the real world. >I had a look in the Paquet BCRAN book, but couldn't find anything referring >to maximum bandwidth of X.25. I would check the RFCs, but due to a cable >problem internet access to most sites from Australia is currently woeful. >However, in the BCRAN book, there is the output of a 'show int' command, >which shows the bandwidth of a sample X.25 interface as 1544 Kbps. > >Maybe some carriers will only provision X.25 at up to 64 Kbps, but I >suspect that the theoretical maximum speed is higher. X.21 will run at up >to 2Mbps, so possibly the answer is 'E - none of the above', but my guess >is that the Cisco answer is 1.544 Mbps. > >JMcL >-- Forwarded by Jenny Mcleod/NSO/CSDA on 23/11/2000 >09:16 am --- > > >"Hawthorne, Mike MM" <[EMAIL PROTECTED]>@groupstudy.com on >23/11/2000 01:11:11 am > >Please respond to "Hawthorne, Mike MM" <[EMAIL PROTECTED]> > >Sent by: [EMAIL PROTECTED] > > > >To: "'xndr'" <[EMAIL PROTECTED]> > [EMAIL PROTECTED] >cc: > > >Subject: RE: x.25 question help > > > > >Dean, the maximum transmission rate for X.25 is 64Kbps. >This I have confirmed with a Telco. > >Cheers >Mike > >-Original Message- >From: xndr [mailto:[EMAIL PROTECTED]] >Sent: Wednesday, November 22, 2000 12:22 AM >To: [EMAIL PROTECTED] >Subject: Re: x.25 question help > >Hi! > >X.25 is a set of CCITT recomendations for transmitting dato over PDNs >protocol suit, including OSI Layers: Physical, Datalink & Network. > >The speed is on Physical Layer. At the physical layer, the X.25 standard >assumes an X.21 interface, but can also support V.35 and the EIA RS232-D >interfaces. > >X.21 bis is up to 19,2 Kbps, V.35 is up to 2Mbps, and RS232 is up about >115,200 or something like this. > >> I have a question about x.25 transmit rate as following: >> What is the maximum transmission rate for X.25? >> >> A. 56 Kbps >> B. 64 Kbps >> C. 128 Kbps >> D. 1.544 Mbps >> >> Thanks >> >> dean >> >> > > > > >_ >FAQ, list archives, and subscription info: >http://www.groupstudy.com/list/cisco.html >Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] _ FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
RE: x.25 question help
First up, I would like to point out that I have NO hands-on experience of X.25 - this is considering the question from the theoretical Cisco point of view, which doesn't necessarily have anything to do with the real world. I had a look in the Paquet BCRAN book, but couldn't find anything referring to maximum bandwidth of X.25. I would check the RFCs, but due to a cable problem internet access to most sites from Australia is currently woeful. However, in the BCRAN book, there is the output of a 'show int' command, which shows the bandwidth of a sample X.25 interface as 1544 Kbps. Maybe some carriers will only provision X.25 at up to 64 Kbps, but I suspect that the theoretical maximum speed is higher. X.21 will run at up to 2Mbps, so possibly the answer is 'E - none of the above', but my guess is that the Cisco answer is 1.544 Mbps. JMcL -- Forwarded by Jenny Mcleod/NSO/CSDA on 23/11/2000 09:16 am --- "Hawthorne, Mike MM" <[EMAIL PROTECTED]>@groupstudy.com on 23/11/2000 01:11:11 am Please respond to "Hawthorne, Mike MM" <[EMAIL PROTECTED]> Sent by: [EMAIL PROTECTED] To: "'xndr'" <[EMAIL PROTECTED]> [EMAIL PROTECTED] cc: Subject: RE: x.25 question help Dean, the maximum transmission rate for X.25 is 64Kbps. This I have confirmed with a Telco. Cheers Mike -Original Message- From: xndr [mailto:[EMAIL PROTECTED]] Sent: Wednesday, November 22, 2000 12:22 AM To: [EMAIL PROTECTED] Subject: Re: x.25 question help Hi! X.25 is a set of CCITT recomendations for transmitting dato over PDNs protocol suit, including OSI Layers: Physical, Datalink & Network. The speed is on Physical Layer. At the physical layer, the X.25 standard assumes an X.21 interface, but can also support V.35 and the EIA RS232-D interfaces. X.21 bis is up to 19,2 Kbps, V.35 is up to 2Mbps, and RS232 is up about 115,200 or something like this. > I have a question about x.25 transmit rate as following: > What is the maximum transmission rate for X.25? > > A. 56 Kbps > B. 64 Kbps > C. 128 Kbps > D. 1.544 Mbps > > Thanks > > dean > > _ FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
RE: x.25 question help
Title: RE: x.25 question help Dean, the maximum transmission rate for X.25 is 64Kbps. This I have confirmed with a Telco. Cheers Mike -Original Message- From: xndr [mailto:[EMAIL PROTECTED]] Sent: Wednesday, November 22, 2000 12:22 AM To: [EMAIL PROTECTED] Subject: Re: x.25 question help Hi! X.25 is a set of CCITT recomendations for transmitting dato over PDNs protocol suit, including OSI Layers: Physical, Datalink & Network. The speed is on Physical Layer. At the physical layer, the X.25 standard assumes an X.21 interface, but can also support V.35 and the EIA RS232-D interfaces. X.21 bis is up to 19,2 Kbps, V.35 is up to 2Mbps, and RS232 is up about 115,200 or something like this. > I have a question about x.25 transmit rate as following: > What is the maximum transmission rate for X.25? > > A. 56 Kbps > B. 64 Kbps > C. 128 Kbps > D. 1.544 Mbps > > Thanks > > dean > > > _ > FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html > Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] > _ FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] __ Disclaimer and confidentiality note Everything in this e-mail and any attachments relating to the official business of Standard Bank Investment Corporation (Stanbic) is proprietary to the company. It is confidential, legally privileged and protected by law. Stanbic does not own and endorse any other content. Views and opinions are those of the sender unless clearly stated as being that of Stanbic. The person addressed in the e-mail is the sole authorised recipient. Please notify the sender immediately if it has unintentionally reached you and do not read, disclose or use the content in any way. Stanbic can not assure that the integrity of this communication has been maintained nor that it is free of errors, virus, interception or interference. ___
Re: x.25 question help
Hi! X.25 is a set of CCITT recomendations for transmitting dato over PDNs protocol suit, including OSI Layers: Physical, Datalink & Network. The speed is on Physical Layer. At the physical layer, the X.25 standard assumes an X.21 interface, but can also support V.35 and the EIA RS232-D interfaces. X.21 bis is up to 19,2 Kbps, V.35 is up to 2Mbps, and RS232 is up about 115,200 or something like this. > I have a question about x.25 transmit rate as following: > What is the maximum transmission rate for X.25? > > A. 56 Kbps > B. 64 Kbps > C. 128 Kbps > D. 1.544 Mbps > > Thanks > > dean > > > _ > FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html > Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] > _ FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: x.25 question help
I don't know what happened to my earlier response.. for some reason, the message forwarded without any comment from me.. ? anyway.. I know that X.25 can run at 1.544... to the people that answered 2MB... is that supposed to be running over an E circuit or something? - Original Message - From: "Phil Barker" <[EMAIL PROTECTED]> To: "Zhang Jin" <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]> Sent: Tuesday, November 21, 2000 5:27 PM Subject: Re: x.25 question help > B > --- Zhang Jin <[EMAIL PROTECTED]> wrote: > Dear > group, > > > > I have a question about x.25 transmit rate as > > following: > > What is the maximum transmission rate for X.25? > > > > A. 56 Kbps > > B. 64 Kbps > > C. 128 Kbps > > D. 1.544 Mbps > > > > Thanks > > > > dean > > > > > > _ > > FAQ, list archives, and subscription info: > > http://www.groupstudy.com/list/cisco.html > > Report misconduct and Nondisclosure violations to > [EMAIL PROTECTED] > > > > Do You Yahoo!? > Get your free @yahoo.co.uk address at http://mail.yahoo.co.uk > or your free @yahoo.ie address at http://mail.yahoo.ie > > _ > FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html > Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] _ FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: x.25 question help
B --- Zhang Jin <[EMAIL PROTECTED]> wrote: > Dear group, > > I have a question about x.25 transmit rate as > following: > What is the maximum transmission rate for X.25? > > A. 56 Kbps > B. 64 Kbps > C. 128 Kbps > D. 1.544 Mbps > > Thanks > > dean > > > _ > FAQ, list archives, and subscription info: > http://www.groupstudy.com/list/cisco.html > Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] Do You Yahoo!? Get your free @yahoo.co.uk address at http://mail.yahoo.co.uk or your free @yahoo.ie address at http://mail.yahoo.ie _ FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: x.25 question help
>From my studies, the maximum speed for X.25 is 2MB/s. Guy Tal wrote: > - Original Message - > From: "Zhang Jin" <[EMAIL PROTECTED]> > Newsgroups: groupstudy.cisco > To: <[EMAIL PROTECTED]> > Sent: Monday, November 20, 2000 7:58 PM > Subject: x.25 question help > > > Dear group, > > > > I have a question about x.25 transmit rate as following: > > What is the maximum transmission rate for X.25? > > > > A. 56 Kbps > > B. 64 Kbps > > C. 128 Kbps > > D. 1.544 Mbps > > > > Thanks > > > > dean > > > > > > _ > > FAQ, list archives, and subscription info: > http://www.groupstudy.com/list/cisco.html > > Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] > > _ > FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html > Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] _ FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
RE: x.25 question help
Title: RE: x.25 question help I don't have my CCITT Blue book anymore but I want to say its 64k connecting to a PDN (Public Data Network) this is a serial connection. Now days though, you could create an x.25 connection over ethernet which would change the above rate. -Original Message- From: Guy Tal [mailto:[EMAIL PROTECTED]] Sent: Monday, November 20, 2000 9:52 PM To: Zhang Jin Cc: [EMAIL PROTECTED] Subject: Re: x.25 question help - Original Message - From: "Zhang Jin" <[EMAIL PROTECTED]> Newsgroups: groupstudy.cisco To: <[EMAIL PROTECTED]> Sent: Monday, November 20, 2000 7:58 PM Subject: x.25 question help > Dear group, > > I have a question about x.25 transmit rate as following: > What is the maximum transmission rate for X.25? > > A. 56 Kbps > B. 64 Kbps > C. 128 Kbps > D. 1.544 Mbps > > Thanks > > dean > > > _ > FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html > Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] _ FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: [Re: x.25 question help]
The Maximum Speed for X.25 is 2MB/s Regards Azhar Soomro "Guy Tal" <[EMAIL PROTECTED]> wrote: - Original Message - From: "Zhang Jin" <[EMAIL PROTECTED]> Newsgroups: groupstudy.cisco To: <[EMAIL PROTECTED]> Sent: Monday, November 20, 2000 7:58 PM Subject: x.25 question help > Dear group, > > I have a question about x.25 transmit rate as following: > What is the maximum transmission rate for X.25? > > A. 56 Kbps > B. 64 Kbps > C. 128 Kbps > D. 1.544 Mbps > > Thanks > > dean > > > _ > FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html > Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] _ FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] Get free email and a permanent address at http://www.netaddress.com/?N=1 _ FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: x.25 question help
- Original Message - From: "Zhang Jin" <[EMAIL PROTECTED]> Newsgroups: groupstudy.cisco To: <[EMAIL PROTECTED]> Sent: Monday, November 20, 2000 7:58 PM Subject: x.25 question help > Dear group, > > I have a question about x.25 transmit rate as following: > What is the maximum transmission rate for X.25? > > A. 56 Kbps > B. 64 Kbps > C. 128 Kbps > D. 1.544 Mbps > > Thanks > > dean > > > _ > FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html > Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] _ FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]