ATM Bit rate [7:2256]
Guys, i`m looking for a good explanation of what this is... i looked on the archives and cisco site,but beleive i am bieng thick . according to cisco the bit rate comes in various flavours UBR,VBR,CBRbut am i getting this complete leg-before-arm i thought the bit rate was a messunment of how fast the link was ??? i don`t get it ...some-one put me out of my misery thanks steve :-$ _ Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com. Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=2256&t=2256 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
RE: ATM Bit rate [7:2256]
I am in a similar situation. The link below provides some good reading, but nothing definitive. I think the type of bit-rate depends on many factors : 1) Type of traffic (real time, non-real time, bursty, constant) 2) Type of VC (switched or PVC) 3) Traffic shaping capability 4) ATM networks provider congestion management capability http://www.cisco.com/warp/public/121/index.shtml Dion > -Original Message- > From: Stephen Skinner [SMTP:[EMAIL PROTECTED]] > Sent: Friday 27 April 2001 15:40 > To: [EMAIL PROTECTED] > Subject: ATM Bit rate [7:2256] > > Guys, > i`m looking for a good explanation of what this is... > > i looked on the archives and cisco site,but beleive i am bieng thick . > > according to cisco the bit rate comes in various flavours > > UBR,VBR,CBRbut am i getting this complete leg-before-arm > > i thought the bit rate was a messunment of how fast the link was ??? > > i don`t get it ...some-one put me out of my misery > > thanks > > steve :-$ > _ > Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com. > FAQ, list archives, and subscription info: > http://www.groupstudy.com/list/cisco.html > Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] * DISCLAIMER: The information contained in this e-mail may be confidential and is intended solely for the use of the named addressee. Access, copying or re-use of the e-mail or any information contained therein by any other person is not authorized. If you are not the intended recipient please notify us immediately by returning the e-mail to the originator. Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=2266&t=2256 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: ATM Bit rate [7:2256]
At 10:39 AM 4/27/01 -0400, Stephen Skinner wrote: >Guys, >i`m looking for a good explanation of what this is... > >i looked on the archives and cisco site,but beleive i am bieng thick . > >according to cisco the bit rate comes in various flavours > >UBR,VBR,CBRbut am i getting this complete leg-before-arm > >i thought the bit rate was a messunment of how fast the link was ??? > >i don`t get it ...some-one put me out of my misery > >thanks > >steve :-$ They are the types of "QoS". Service classes defined by the ATM standards. (UNI 4.0) Unspecified Bit Rate (AAL5, pretty much Best Effort) Variable Bit Rate (AAL2, for variable bit video, never really took off) Constant Bit Rate (AAL1, for constant, guaranteed bandwidth) There is also ABR (available bit rate), (takes left over bandwidth). For your information, AAL0 is raw ATM cells, and AAL3/4 is combined together. In theory, AAL3/4 is absolutely obsoleted by AAL5 since the cell tax would have been higher. (CRCs in EACH cell vs each PDU (9180 octets or so)). Also, VBR has two forms, Non-real time and real time. The actual ATM adaption type I listed above may vary, as ATM is very complicated and the standards get fuzzed left and right. I hope anyone with more definitive knowledge can help you fill in the gaps I may have left. -Carroll Kong Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=2273&t=2256 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: ATM Bit rate [7:2256]
many thanks... also who-ever recommended the atm book nice one steve :-) >From: "Carroll Kong" >Reply-To: "Carroll Kong" >To: [EMAIL PROTECTED] >Subject: Re: ATM Bit rate [7:2256] >Date: Fri, 27 Apr 2001 12:07:33 -0400 > >At 10:39 AM 4/27/01 -0400, Stephen Skinner wrote: > >Guys, > >i`m looking for a good explanation of what this is... > > > >i looked on the archives and cisco site,but beleive i am bieng thick . > > > >according to cisco the bit rate comes in various flavours > > > >UBR,VBR,CBRbut am i getting this complete leg-before-arm > > > >i thought the bit rate was a messunment of how fast the link was ??? > > > >i don`t get it ...some-one put me out of my misery > > > >thanks > > > >steve :-$ > >They are the types of "QoS". Service classes defined by the ATM >standards. (UNI 4.0) > >Unspecified Bit Rate (AAL5, pretty much Best Effort) >Variable Bit Rate (AAL2, for variable bit video, never really took off) >Constant Bit Rate (AAL1, for constant, guaranteed bandwidth) > >There is also ABR (available bit rate), (takes left over bandwidth). > >For your information, AAL0 is raw ATM cells, and AAL3/4 is combined >together. In theory, AAL3/4 is absolutely obsoleted by AAL5 since the cell >tax would have been higher. (CRCs in EACH cell vs each PDU (9180 octets or >so)). > >Also, VBR has two forms, Non-real time and real time. The actual ATM >adaption type I listed above may vary, as ATM is very complicated and the >standards get fuzzed left and right. I hope anyone with more definitive >knowledge can help you fill in the gaps I may have left. > > > > >-Carroll Kong >FAQ, list archives, and subscription info: >http://www.groupstudy.com/list/cisco.html >Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] _ Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com. Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=2554&t=2256 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
RE: ATM Bit rate [7:2256]
UBR,VBR,CBR,AND ABR are atm service categories for QOS. regards, Mark, -Original Message- From: Stephen Skinner [mailto:[EMAIL PROTECTED]] Sent: Friday, April 27, 2001 7:40 AM To: [EMAIL PROTECTED] Subject: ATM Bit rate [7:2256] Guys, i`m looking for a good explanation of what this is... i looked on the archives and cisco site,but beleive i am bieng thick . according to cisco the bit rate comes in various flavours UBR,VBR,CBRbut am i getting this complete leg-before-arm i thought the bit rate was a messunment of how fast the link was ??? i don`t get it ...some-one put me out of my misery thanks steve :-$ _ Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com. FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=2644&t=2256 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: ATM Bit rate [7:2256]
Carroll, may i be so bold as to ask another question the VCI/VPI numbersi was led to beleive that this are carrier supplied and have no Overall meaning(just the DLCI type)...but i have seen that some do have meaningi searched CCO but fpound squat...any links or info you could provide would be most welcome Thanks in advance steve >From: "Carroll Kong" >Reply-To: "Carroll Kong" >To: [EMAIL PROTECTED] >Subject: Re: ATM Bit rate [7:2256] >Date: Fri, 27 Apr 2001 12:07:33 -0400 > >At 10:39 AM 4/27/01 -0400, Stephen Skinner wrote: > >Guys, > >i`m looking for a good explanation of what this is... > > > >i looked on the archives and cisco site,but beleive i am bieng thick . > > > >according to cisco the bit rate comes in various flavours > > > >UBR,VBR,CBRbut am i getting this complete leg-before-arm > > > >i thought the bit rate was a messunment of how fast the link was ??? > > > >i don`t get it ...some-one put me out of my misery > > > >thanks > > > >steve :-$ > >They are the types of "QoS". Service classes defined by the ATM >standards. (UNI 4.0) > >Unspecified Bit Rate (AAL5, pretty much Best Effort) >Variable Bit Rate (AAL2, for variable bit video, never really took off) >Constant Bit Rate (AAL1, for constant, guaranteed bandwidth) > >There is also ABR (available bit rate), (takes left over bandwidth). > >For your information, AAL0 is raw ATM cells, and AAL3/4 is combined >together. In theory, AAL3/4 is absolutely obsoleted by AAL5 since the cell >tax would have been higher. (CRCs in EACH cell vs each PDU (9180 octets or >so)). > >Also, VBR has two forms, Non-real time and real time. The actual ATM >adaption type I listed above may vary, as ATM is very complicated and the >standards get fuzzed left and right. I hope anyone with more definitive >knowledge can help you fill in the gaps I may have left. > > > > >-Carroll Kong >FAQ, list archives, and subscription info: >http://www.groupstudy.com/list/cisco.html >Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] _ Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com. Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=2719&t=2256 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: ATM Bit rate [7:2256]
At 09:13 AM 5/1/01 +, Stephen Skinner wrote: >Carroll, > >may i be so bold as to ask another question > >the VCI/VPI numbersi was led to beleive that this are carrier supplied >and have no Overall meaning(just the DLCI type)...but i have seen that >some do have meaningi searched CCO but fpound squat...any links or >info you could provide would be most welcome > >Thanks in advance > >steve VCI == Virtual Circuit Identifier VPI == Virtual Path Identifier Together they define an "end-to-end" circuit, but you are correct, they only hold local significance. The actual VCI/VPI may change during it's transit to the final destination (once it hits a switch, the pair can be totally changed), just like a DLCI. They are some reserved VCI/VPIs like (x can be any integer from 0 to 256?). (not sure on the limits here, VPIs are not supposed to be as common, the VCI probably have up to 65535 as the upper bound). VPI/VCI x/1 and as the others mentioned 0/5 0/16 They are reserved for signalling or metasignalling. (UNI). I believe there are even some well known DLCIs as well (reserved). I suppose you 'could' use them, at your own peril. -Carroll Kong Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=2736&t=2256 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: ATM Bit rate [7:2256]
Hi, A bit rate is a bit rate, however there is several QoS factor that you forget to count. For example there is : Cell Delay Variation Tolerance. Cell Transfer Delay. Cell Lost Priority So a ABR, UBR, CBR, VBR of the same bit rate at 125.000 bps might get a different result. Hope this helps even a bit :) Regards, Leonard Ong, CCIE Candidate, CCNP R&S+Voice, CCDP R&S, CSE, CCSA, Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=2835&t=2256 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
