Re: what'meaning out of band or in-band
Hi, In band signalling uses the same channel uses the same channel for signalling which is used for passing data. For example consider the ordinary telephone in our daily use. The signal is sent on the same wire through which we will send the data also.Where as in outof band signalling we will be using the seperate channel for signalling purpose. Consider for example ISDN, we will be using seperate D-channel for signalling purpose. Hope this helps a little bit. Thanks Subbi. On Mon, 9 Oct 2000, rsma wrote: hi: I am not clear what's meaning of "out of band and in band",when I read about CCSCAS. thinks a lot **NOTE: New CCNA/CCDA List has been formed. For more information go to http://www.groupstudy.com/list/Associates.html _ 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] **NOTE: New CCNA/CCDA List has been formed. For more information go to http://www.groupstudy.com/list/Associates.html _ 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: some confusing about BGP
Hi, A loopback interface is used because it will be always up and more over it's an logical interface. In wan connection it will be used greatly because the interface will be always up.Please provide the diagram or picture for second question. -Subbi. ___ 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: BGP !!!
Hi, BGP is used to create inter domain free loop routing between AS. It uses Path Vector as its metric. It carries the number of the AS as it traverse the network to avoid loops. Hope this helps you. -Subbi. Raees Ahmed Shaikh wrote: I was always hearing about the great BGP as a very scalar protocol with lots of advantages, and suddenly I was a little shocked to learn that it was a variant of the distance-vector-protocol I have read many books praising the qualities of link-state protocols and mentioning the disadvantages of distance vector protocols I am a bit confused as a matter of preference what should I generally speak about distance vector protocol V/s Link state protocols. Lots of lessons and surprises to be learnt more, Thanks and Regards, Pls .If somebody can elaborate and explain that will be great. Shaikh Raees Ahmed, Microsoft Certified Systems Engineer, Cisco Certified Network Associate, Systems Network, IT Division. ___ 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]
multicast address
Hi, Can somebody explain me how to convert an multicast IP address for e.g (224.0.0.6) into multicast mac address. TIA, -Subbi. ___ 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]
Transit traffic
Hi, Could somebody there can explain me what do you mean by transit traffic in the contest of BGP . What kind of information does it carries. TIA, -Subbi. ___ 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: What is route map ?
Hi Tapas, Route map is used for controlling and modify routing information. This is done by definfing conditions for distributing routes from one routing protocol to another or controlling routing information when injected in and out of BGP. Hope this helps. Thanks, -Subbi. Tapas Das wrote: What is route map ? Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.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: Some ISDN PRI questions
Hi Adam, Thanks for your clarification . I am having one more doubt. Where comes the concept of red and yellow alaram. Thanks, -Subbi. Adam Quiggle wrote: Hey Ole, It really is 8000 samples. The number 8000 comes from Nyquist's theorem which in a nutshell states that in order to properly represent an analog signal in digital form we must sample twice the frequency range. Since an analog signal is represented from 0-4Khz we must sample an analog signal (2*4000) times a second in order to transport it with minimal loss. Thus we get 8000 samples a second. Each sample is encoded with 8 bits to represent an analog signal at anyone time, thus we get: 8 bits/samples * 8000 samples/sec = 64,000 bits/sec (look familiar?) Now, if we look at a single frame of a channelized T1 we can see that we have twenty-four 8-bit timeslots plus a single bit for framing or: Data Channels (23B+1D) 24 channels * 8 bits/sample * 8000 samples/second = 1,536,000bps Framing Bit 1 bit/sample * 8000 samples/second = 8000 bps So, we can see that for data we have 1,536,000 bps and 8,000 bps for framing, which equals 1,544,000 bps. This is why people think of a T1 as 1.544Mb but it's true throughput is only 1.536Mb. So, what is the framing bit used for? Framing allows the CSU/DSU to find the timeslots in the channelized T1. Remember, that 8000 T1 frames are flying out of the circuit every second, and the CSU/DSU must know how to find the T1 frames in this circuit (don't ask me why, but I can't stop thinking of Lucille Ball in the bon/bon episode :-) In order to maintain sync, the CSU/DSU must grab every 193rd bit off of the line, string them together and see if it forms the "pattern" it is looking for. The type of framing used describes the pattern to look for. When using Superframing twelve of these bits are strung together and must form the following pattern of "100011011100". If it doesn't form this pattern, the CSU/DSU is said to slip and it must then resync its timing to the signal. Extended Superframing is an extension of Superframing and instead of trying to collect twelve of these framing bits, it collects 24 of these bits for syncing to the signal. So, what about robbed bit signaling (RBS)? RBS is not a function of what type of framing you are using. RBS also known as Channel Associated Signaling (CAS) is a technique in which supervisory and signaling information is sent by removing the 8th bit of the 6th and 12th Superframe or the 8th bit of the 6th, 12th, 18th and 24th bit of the extended superframe. The overall affect for those using Channel Associated Signaling is that you don't need a D channel, however all your B channels use 56kbps. You can find more information on the following topics in McGraw Hill BCRAN: http://www.bookpool.com/.x/p9zwbh4yt6/sm/0072124806 Channelized T1/E1 frame format: 208-213 Framing and linecoding: 226-228 Robbed bit signaling/Channel Associated Signaling: 230-231 The purpose of this book was to go beyond the Ciscopress material, which focuses on the BCRAN exam material only and add information that seems to have been ignored by Ciscopress's BCRAN. You will note that in this book, when a topic is not covered on the BCRAN exam, there is a note indicating such, so that you don't review material not required for the examok shameless plug over... :-) Adam Quiggle At 05:31 PM 7/11/00, Ole Drews Jensen wrote: Hi Subbi, You are dragging me out in orbit now, but I'll try to hang on. To get back to the ISDN PRI... The 8000 samples, are you sure that it's not 8 k-samples (8*1024) = 8192 samples??? That would make sense since the 192 bits (24*8) multiplied with 8192 equals 1572864 which again equals 1536 kbps (1572864/1024). That brings us back to 24 channels where the last one is only used for signaling - not data. Ole ~~ Ole Drews Jensen Systems Network Manager CCNA, MCSE, MCP+I RWR Enterprises, Inc. [EMAIL PROTECTED] ~~ -Original Message- From: Subramanian Nallasivam [mailto:[EMAIL PROTECTED]] Sent: Tuesday, July 11, 2000 4:14 PM To: Ole Drews Jensen Cc: [EMAIL PROTECTED] Subject: Re: Some ISDN PRI questions Hi Ole, Let me take the case of T1. In T1 all the 24 channel are used for sending data. There will be one framing bit which constitiute to 193 bits. So 193 * 8000 = 1544 kbps. And one bit from every sixth frame in case of superframe(which consists of 12 T1/DS1 frames) will be robbed for signalling. The robbed bit will be the least significant bit and this concept is known as robbed-bit signalling. If I am wrong then please correct me. Thanks, -Subbi. Ole Drews Jensen wrote: Hi Subbi, That would still only leave 184 * 8000 = 1472000 bps or (1472000/1024) 1437.5 kbps for data. Ole ~~ Ole Drews Jensen
Re: Some ISDN PRI questions
Hi, I am new to ISDN concepts, but here they are We have 23 DSO for carrying data. Each channel carries 8 bit word or something. So 23 * 8 = 184 One channel is used for carrying signal . So the number comes out to be 184 + 8 = 192 Since 8000 samples are sampled per second , the calculation comes to be 192 * 8000 = 1536 Kbps. T1 uses in-band signalling ( uses same data channel for signalling also) where as ISDN PRI uses out-band signalling (uses seperate channels for signals). I am new to ISDN cocepts. If I am wrong please correct me. Thanks, -Subbi. Ole Drews Jensen wrote: The ISDN BRI has two 64 kbps B channels and one 16 kbps D channel. That gives us a maximum of 128 kbps bandwidth for data which makes sense. The ISDN PRI has twenty three 64 kbps B channels and one 64 kbps D channel. That should give us a maximum of 1472 kbps bandwidth for data, and not 1536 kbps as normally specified unless it is possible to use the D channel for data too ??? The ISDN PRI in Europe has thirty 64 kbps B channels and one 64 kbps D channel. That should give us a maximum of 1920 kbps for data, and not 2048 kbps as normally specified even if the D channel is used for data too. Are these numbers just used because it's easier to remember the 1536 and 2048 values, or is there a hidden factor here??? A last question: I sometimes hear people refer to an ISDN PRI as a T1. The T1 has the same amount of channels and bandwidth, so the question is - are there really a big difference between these two specifications, or is it more or less the same??? Some or all of these questions might be answered later on in my book, but I can't wait any longer - I want to know NOW :-) Thanks for any comments on this. Ole ~~ Ole Drews Jensen Systems Network Manager CCNA, MCSE, MCP+I RWR Enterprises, Inc. [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] ___ 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: Some ISDN PRI questions
Hi Ole, Let me take the case of T1. In T1 all the 24 channel are used for sending data. There will be one framing bit which constitiute to 193 bits. So 193 * 8000 = 1544 kbps. And one bit from every sixth frame in case of superframe(which consists of 12 T1/DS1 frames) will be robbed for signalling. The robbed bit will be the least significant bit and this concept is known as robbed-bit signalling. If I am wrong then please correct me. Thanks, -Subbi. Ole Drews Jensen wrote: Hi Subbi, That would still only leave 184 * 8000 = 1472000 bps or (1472000/1024) 1437.5 kbps for data. Ole ~~ Ole Drews Jensen Systems Network Manager CCNA, MCSE, MCP+I RWR Enterprises, Inc. [EMAIL PROTECTED] ~~ -Original Message- From: Subramanian Nallasivam [mailto:[EMAIL PROTECTED]] Sent: Tuesday, July 11, 2000 3:54 PM To: Ole Drews Jensen Cc: [EMAIL PROTECTED] Subject: Re: Some ISDN PRI questions Hi, I am new to ISDN concepts, but here they are We have 23 DSO for carrying data. Each channel carries 8 bit word or something. So 23 * 8 = 184 One channel is used for carrying signal . So the number comes out to be 184 + 8 = 192 Since 8000 samples are sampled per second , the calculation comes to be 192 * 8000 = 1536 Kbps. T1 uses in-band signalling ( uses same data channel for signalling also) where as ISDN PRI uses out-band signalling (uses seperate channels for signals). I am new to ISDN cocepts. If I am wrong please correct me. Thanks, -Subbi. Ole Drews Jensen wrote: The ISDN BRI has two 64 kbps B channels and one 16 kbps D channel. That gives us a maximum of 128 kbps bandwidth for data which makes sense. The ISDN PRI has twenty three 64 kbps B channels and one 64 kbps D channel. That should give us a maximum of 1472 kbps bandwidth for data, and not 1536 kbps as normally specified unless it is possible to use the D channel for data too ??? The ISDN PRI in Europe has thirty 64 kbps B channels and one 64 kbps D channel. That should give us a maximum of 1920 kbps for data, and not 2048 kbps as normally specified even if the D channel is used for data too. Are these numbers just used because it's easier to remember the 1536 and 2048 values, or is there a hidden factor here??? A last question: I sometimes hear people refer to an ISDN PRI as a T1. The T1 has the same amount of channels and bandwidth, so the question is - are there really a big difference between these two specifications, or is it more or less the same??? Some or all of these questions might be answered later on in my book, but I can't wait any longer - I want to know NOW :-) Thanks for any comments on this. Ole ~~ Ole Drews Jensen Systems Network Manager CCNA, MCSE, MCP+I RWR Enterprises, Inc. [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] ___ 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]
