DeShazo: Mixing apples and cucumbers in the discussion. ISDN is a switched service, DSL is a network service that can run over ISDN (as a transport). My experience in Europe (to compliment what Colin wrote) is that it will never (no time soon) go away. DTG: Thursday, March 25, 2004 at 11:46:12. Subject: Re: Future of ISDN From: Darryl Morris Date: Thu, 25 Mar 2004 11:13:28 -0500 To: INFOSEC-LIST@lists.mitre.org Don: It is correct to say that ISDN has largely been eclipsed by DSL as the interface of choice for individual DATA transport access, but its a stretch to say is its going away based on just that, and without distinguishing between Narrowband and Primary Rate ISDN. ISDN is very well entrenched as a preferred interface for connecting private voice networks (e.g. PBXs) to the public switched telephone network (PSTN). Given the fact that PR ISDN is available and tariffed just about universally in the US and Europe for this purpose it is unlikely that it would be going away anytime soon. Legacy support within the telephony world is long standing as testified by the fact that analog telecom interfaces of the 1950s are still pretty much available. What was not clear in Dan's question was the application that prompted the sponsor concern. If it was data transport access the point made about DSL are germane. If it was related to access for secure voice (e.g. STEs) the key issues to answer differ. I have not seen any specific studies on the subject but I woudl very much doubt support for narrow band ISDN in either the public network or private networking (e.g. PBXs) will be going away in 5-7 years. At leat in the public networks the Public Utility Commissions are very reluctant to allow Carriers to dropped such interfaces and in the private network world avialability of interfaces to support backward compatibility of (standard interface) legacy end user equipment has historically been a market requirement. For these reasons, at least in the telephony service arena, it is unlikely things will change dramatically in the next 5 years. There is widespread interest in transitioning to VoIP but as yet in the public arena a mature national infrastructure for this has not emerged and is probably several years in the offing. -----Original Message----- From: Don Bailey [mailto:baileydl@mitre.org] Sent: Thursday, March 25, 2004 10:07 AM To: INFOSEC-LIST@lists.mitre.org Subject: Re: Future of ISDN ISDN has been largely replaced by DSL technology, which includes DSL over ISDN, or IDSL. Other than an alternative technology / Internet backup, or credit card terminal / PoS that prefers quick negotiation without all the modem squawking, there's no need for ISDN. Anywhere. ISDN IS rather mature in comparison to DSL and will probably continue to be an available voice & data delivery option from ILECs for the foreseeable future (5-7 years I'd say), but given its cost vs performance, most people will simply choose a DSL technology before ISDN. Sincerely, Don dan wrote: >> My sponsor is trying to find out if ISDN will be going away anytime >> soon. Both domestically and internationally. Does anyone have any >> analysi papers that show the outlook for ISDN. I know it is still used >> quite a bit overseas. -- Don Bailey Lead INFOSEC Engineer/Scientist Secure Information Technology The MITRE Corporation 703-883-6230