@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ Date: Tue, 23 Jan 1996 From: •••@••.••• (Allan Bradley) Subject: Re: cr> ...building a parallel isochronous Internet Richard Moore wrote: > I'd welcome _a bit_ of techhie talk on the list about the likely >new net architectures, and how Internet might co-exist or inter-operate >with them -- just so we can have an informed model of the likely scenarios. F.Y.I I wrote this some months ago. Maybe it will stir some interest. First, I breakdown the new "Communications" market into three (3) categories: 1. Technology (applications, hardware/software, etc - of all sorts) 2. Bandwidth (the size of the pipes to support the Technology) and 3. Distribution (the layout allocation of the pipes, e.g., fiber, satellite, cable, etc.). ATM (Asynchronous Transfer Mode) Network Technology ATM takes data information (voice, video and data) and chops it up into small chunks which are called "cells". These cells are essentially segmented in the hardware of LAN/WAN Switch Hubs into "virtual circuits". Within these hubs are virtual switching engines (in hardware) which forward the cells from their source to their destination. The problem is that massive amounts of virtual circuits can be immense. For example, lets say you need to connect 200 buildings - that turns into a 200 by 200 possible switch matrix which means 40,000 potential switched circuits. This tends to mean that you have to be selective on what sites get what resources and management of switching fabrics can be expensive. Although the switching is transparent to the user and the virtual circuits are basically self defining, the issue of really controlling the switching fabric is paramount. A switching fabric (hardware based) is called connection oriented because a virtual end-to-end circuit has been established (required for voice, video and data streams) and is load independent (more users performance integrity remains the same). The Internet is based on connectionless data or datagram schemes. The main difference is that the Internet is software based (TCP/IP) and therefore highly programmable - the drawback is that it is slow and unpredictable (jerky video) and load dependent (more users worse performance) - the advantage is that it self allocating and managing based on user addresses - not circuits. I think a key difference is that the Internet is user controlable by addresses, ATM will be more vendor controlled by circuits. Enter the standards bodies (ATM Forum) basically made up of network hardware, software vendors and phone companies. Best of all worlds is to combine the connection data streaming performance with the managing software of connectionless control. The definition of what are called Adaptation Layers were established. There is still huge debates on what these Adaptation Layers will really provide and to what level they will be a true industry open standard. For last few years there has been a big battle on the standards committees on how to price switched circuits. The phone companies wanted a header to be put on the cell so that Bandwidth on Demand services could be defined (essentially the more bandwidth you use the more you pay) the network vendors did not want a cell header because it would slow performance and create more switching overhead. I believe now there will be to two categories of switched connectivity and will be allocated on a platform by platform basis. Which is fine because both are needed for different markets. The real difference is that as a communications company (based on the phone model) I could run a line and price it as a dedicated path (pipe) with only a singular associated bandwidth payload - which is the way it is today. With new technologies I can take that same path and create multiple aggregate payloads and the physical rate structure is the same to the communications company. What does this mean. Well for example, lets take two different public sites: a residential community and a business park. And for the sake of universal access both have been wired with the same amount of fiber, copper, etc. to support high-end communications. Both from a communications company perspective have cost exactly the same amount as far as distribution. But the technology levels given the business park will require a thousand times more bandwidth than that of the residential community. Where do you think the profit margin and the emphasis is going to be? It will be about circuit control and pricing. The thing to remember is that with ATM your getting more capability given the existing physical infrastructure - is it a coincidence that many Public Utilities Commissions tie usage rates to the cost of distribution, but with the advent of technologies like ATM, deregulation and unbundling of rate structures are now a strong part of the Bill. The Telecom Bill transport fairness rules are based on old vertical market allocation, when the real money will be in horizontal market bandwidth distribution. That is the monopoly danger. That is why I harp on defining the models. If you have the money for the technology, you have the huge advantage in the market. My concern is that schools, public services, city communities may get the short end of the stick, because it is a distribution bandwidth market and they need cheap bandwidth and that could lower market margins. The investment cost in these technologies today is very high. The problem is that regulations need to include bandwidth distribution and not exclusively physical distribution as the basis of universal access/distribution. Allan Bradley ConsulMetrix, Inc. Setting the Standards in Technology Consulting @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ ~=-=-=-=-=-=-=-=~=-=-=-=-=-=-=-=-=~--~=-=-=-=-=-=-=-=-=~=-=-=-=-=-=-=-=-=~ Posted by Richard K. Moore (•••@••.•••) Wexford, Ireland Cyber-Rights: http://www.cpsr.org/cpsr/nii/cyber-rights/ CyberLib: http://www.internet-eireann.ie/cyberlib Materials may be reposted in their entirety for non-commercial use. ~=-=-=-=-=-=-=-=~=-=-=-=-=-=-=-=-=~--~=-=-=-=-=-=-=-=-=~=-=-=-=-=-=-=-=-=~