From: Greg Slingerland@MITEL on 08/03/99 10:07 AM Hello Everyone,
This is as good discussion thread as any to make a comment about the usage of the "RJ" designations. This term is grossly misused in the Telecommunications Industry and I want to do my tiny part to help correct it. This does not attempt to answer the original question raised by the person seeking connector information for and ISDN service and for that I am sorry. Regardless, please indulge me for a moment. And for those who know what I'm talking about you may read your next message. Everyone, and I mean virtually everyone, uses the term RJ11 to mean the six position miniature telephone connector which is widely used for telephone connection throughout the USA. and Canada (elsewhere in the world as well). Likewise RJ45 is the eight position version. Right?................................ Wrong! The designator "RJ" stands for Registered Jack and has a definite meaning within the US, Federal Communication Commission rules. Any RJ designator means three, I said three, specific things. First is the connector style, which is where most people stop. Second is the service (e.g. loop start, E&M, BRI, etc.). Third is the pinout. For example, an RJ11 is used for Loop Start service over a six position miniature module jack with pins 3 and 4 used. When this same connector and same service is used for two lines the correct designation is RJ14. When used for three lines its an RJ25. Also note that these terms only apply when used in a connection between terminal equipment and the telephone network. For any other usage, even with the same connector, pinout and service, the RJ designation is not applicable. Ever wonder why there is not an RJ term for the four position miniature connector typically used for handsets? That's because its never been used for any network to customer connections! Connectors which do not fall under the FCC but which are still used in the US between terminal equipment and the telephone network are given the SJ designation which means "Standard Jack". There are also configurations used in Network to customer connections which have neither RJ or SJ designators. For a complete and detailed document on these connectors, please refer to the T1E1.1 document "Technical Report #5, Network and Customer Installation Interface Connector Wiring Configuration Catalog". The standards committee T1 can be found at http://www.t1.org/ and the page where this document is located is http://www.t1.org/html/trs.htm and please be aware they do charge $55US for it. FCC's Part 68 (which you can get from the web for free) does contain a lot of these configurations but many are obsolete and there are many new ones which it does not have. This Technical Report is the most current information available. It may even answer some of the questions originally raised. One respondent did elude to this issue by indicating that Canada uses the "CA" designator in place of the US "RJ" designator. This is true for the most part. There are differences here as well in coverage. Not all RJ configurations have a corresponding CA configuration and vice versa. I don't expect this one mail to correct this situation but I hope it will help and has been informative to most or some of you. Even the connector manufacturers themselves get this wrong in their catalogs and sales brochures. Its no wonder those in the industry get this wrong. Generally its those who work in the telecommunications standards formulation committees who understand the proper meaning. I do understand the need for a quick and simple term to refer to a connector. Unfortunately I do not know of one in this case. I'll get off my soap box now, crawl back into my hole, and continue to lurk. I'm sure most of those who subscribe to TREG are lurkers like myself. BTW an RJ45 configuration is used for an analog programmed data jack service which I don't think is at all applicable to ISDN. :-) Greg Slingerland Mitel Corporation P.S. Just to stir the pot and see how many fish I can catch. Do you know that RS-232 no longer exists as a standard! Don't believe me! Go to http://www.tiaonline.org/standards/search_n_order.cfm and enter "232" in the document number window, then press "search". "Dorababu R." <[email protected]> on 08/03/99 07:44:33 AM Please respond to "Dorababu R." <[email protected]> To: [email protected], [email protected] cc: (bcc: Greg Slingerland/Kan/Mitel) Subject: Re: ISDN interface Hi Kim Jensen, I believe it is RJ45. More details at this connectors page. http://www.hwb.acc.umu.se/ Thanks Dorababu [email protected] wrote: > > Dear everybody > > I'm confused about the different use of ISDN connectore in EU and US. > > Our situation is: > > we make a Bri ISDN (TRB 3) interface which uses a RJ45 connection > > we want this interface approved by FCC part 68, BUT will use EU ISDN lay > 1-3 > > But as I can see RJ48 connection is used in the US which differe from RJ45 in > the wiring of the modular jack connector. > > My questions are: > > is RJ45 used in the US/Canada at all ? > > can we have a FCC approval of a EU ISDN ? > > Best regards, > > Mr. Kim Boll Jensen > i-data, Denmark
