RE: total bit rate for BRI
Speaking of evil test creators, the one I've always wondered about is actual T1/DS1 throughput. I believe serial lines are full duplex. So NOW what is the REAL bit rate? ;- Chuck -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]] On Behalf Of Brian Sent: Saturday, October 28, 2000 4:52 PM To: Patrick Bass Cc: [EMAIL PROTECTED] Subject:Re: total bit rate for BRI On Sat, 28 Oct 2000, Patrick Bass wrote: In Cisco internetworking Technology Overview it states... "BRI also provides for framing control and other overhead, brining its total bit rate to 192 kbps." In Cisco Internetwork Design it states... "The D channel signaling protocol comprises Layers 1 through 3 of the OSI reference model, brining its total bit rate to 144 kbps." If I'm taking a Cisco certification exam and the question is "What is the total bit rate of a BRI" and the answers are a) 128 b) 144 c) 192 d) whatever...what's the correct answer? Is it 144 kbps or 192 kbps? You won't have those two answers :) This is sort of like the argument is a T1 1.544 or 1.536. Only the most evil test creator would put both those answers on a test... You seem to understand it quite well. 192 is with framing, 144 is just 2B+D. You can actually use the D channel, but you can't use the framing bits. I realize that it is 192 kbps when you take the 48 kbps for framing into account but considering the fact that two Cisco sources give different totals for "total bit rate" what am I to answer if I wish to get the answer correct? _ FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] --- Brian Feeny, CCNP, CCDP [EMAIL PROTECTED] Network Administrator ShreveNet Inc. (ASN 11881) _ 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: total bit rate for BRI
On Sun, 29 Oct 2000, Chuck Larrieu wrote: Speaking of evil test creators, the one I've always wondered about is actual T1/DS1 throughput. I believe serial lines are full duplex. So NOW what is the REAL bit rate? ;- 1.536Mbps is the actual usable bit rate of a clear channel t1. 8 bits is used for framing. Yes that is in each direction. But if a circuit has 1Mbps incoming and 1Mbps outgoing, you still usually just call it a 1Mbps fdx, instead of 2Mbpsat least I do. I know some peole refer to 100bT fdx as 200Mbpsbut I think its more accurate to say 100Mb/s fdx. Brian Chuck -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]] On Behalf Of Brian Sent: Saturday, October 28, 2000 4:52 PM To: Patrick Bass Cc: [EMAIL PROTECTED] Subject: Re: total bit rate for BRI On Sat, 28 Oct 2000, Patrick Bass wrote: In Cisco internetworking Technology Overview it states... "BRI also provides for framing control and other overhead, brining its total bit rate to 192 kbps." In Cisco Internetwork Design it states... "The D channel signaling protocol comprises Layers 1 through 3 of the OSI reference model, brining its total bit rate to 144 kbps." If I'm taking a Cisco certification exam and the question is "What is the total bit rate of a BRI" and the answers are a) 128 b) 144 c) 192 d) whatever...what's the correct answer? Is it 144 kbps or 192 kbps? You won't have those two answers :) This is sort of like the argument is a T1 1.544 or 1.536. Only the most evil test creator would put both those answers on a test... You seem to understand it quite well. 192 is with framing, 144 is just 2B+D. You can actually use the D channel, but you can't use the framing bits. I realize that it is 192 kbps when you take the 48 kbps for framing into account but considering the fact that two Cisco sources give different totals for "total bit rate" what am I to answer if I wish to get the answer correct? _ FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] --- Brian Feeny, CCNP, CCDP [EMAIL PROTECTED] Network Administrator ShreveNet Inc. (ASN 11881) _ FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] --- Brian Feeny, CCNP, CCDP [EMAIL PROTECTED] Network Administrator ShreveNet Inc. (ASN 11881) _ FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
RE: total bit rate for BRI
At 12:37 PM 10/29/00, Brian wrote: On Sun, 29 Oct 2000, Chuck Larrieu wrote: Speaking of evil test creators, the one I've always wondered about is actual T1/DS1 throughput. I believe serial lines are full duplex. So NOW what is the REAL bit rate? ;- 1.536Mbps is the actual usable bit rate of a clear channel t1. 8 bits is used for framing. Yes that is in each direction. But if a circuit has 1Mbps incoming and 1Mbps outgoing, you still usually just call it a 1Mbps fdx, instead of 2Mbpsat least I do. I know some peole refer to 100bT fdx as 200Mbpsbut I think its more accurate to say 100Mb/s fdx. Brian Brian, I completely agree. If you're at Server A and need to get to Server B through a T1 wan link as seen below: Server A--- Router AT1Router BServer B your data can still only be sent at 1MB/sec. For those that would call it a 2MB/sec connectionWhat would you call the speed limit on a major highway, is it 65mph or 130 mph? Traffic does flow at 65mph in each direction ;-) Chuck's question prompts an even bigger question...What is real? LOL AQ _ FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: total bit rate for BRI
On Sat, 28 Oct 2000, Patrick Bass wrote: In Cisco internetworking Technology Overview it states... "BRI also provides for framing control and other overhead, brining its total bit rate to 192 kbps." In Cisco Internetwork Design it states... "The D channel signaling protocol comprises Layers 1 through 3 of the OSI reference model, brining its total bit rate to 144 kbps." If I'm taking a Cisco certification exam and the question is "What is the total bit rate of a BRI" and the answers are a) 128 b) 144 c) 192 d) whatever...what's the correct answer? Is it 144 kbps or 192 kbps? You won't have those two answers :) This is sort of like the argument is a T1 1.544 or 1.536. Only the most evil test creator would put both those answers on a test... You seem to understand it quite well. 192 is with framing, 144 is just 2B+D. You can actually use the D channel, but you can't use the framing bits. I realize that it is 192 kbps when you take the 48 kbps for framing into account but considering the fact that two Cisco sources give different totals for "total bit rate" what am I to answer if I wish to get the answer correct? _ FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] --- Brian Feeny, CCNP, CCDP [EMAIL PROTECTED] Network Administrator ShreveNet Inc. (ASN 11881) _ FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
