Chapter 3: ISDN Line Ordering and Configuration24 HSIM-W6 User’s GuideTelephone Switch SupportYour telephone company may offer a variety of ISDN switch types. You must contact your serviceprovider and find out which type of ISDN service is available.The following switch types are currently supported by the HSIM-W6 within the U.S.:• National ISDN 1 (NI-1)• AT&T 5ESS with Custom Software• DMS-100Outside of the U.S. the following switch types are currently supported:• NET3 (European ISDN)• NET3SW (European Swiss-variant)• NTT (Nippon Telegraph and Telephone)• KDD (Kokusai Denshin Denwa Co., Ltd.)• French Delta (VN4) switchesISDN BRI Line ConfigurationYou need to order one Basic Rate Interface (BRI) ISDN line from your service provider. The BasicRate Interface ISDN line provides two full duplex 64 (Kbps) B channels used for voice, data, fax,etc. and one full duplex 16 Kbps channel used for signaling. Each B channel can be used for a call;i.e., two calls can occur at the same time. Services vary from individual service providers.The service provider requires some information from you about your configuration. You mustprovide your service provider with the required switch settings for the provider’s telephone switch(see Telephone Switch Parameters in this chapter). Consult with your service provider at leasttwo months before requiring the installation and use of the ISDN service.NOTEFull 64 Kbps for each channel (called clear channel) may not be available across theentire communications link. Today, many providers still use in-band signaling(the 8 Kbps signaling is taken from the B channel bandwidth) so that you may onlyachieve a 56 Kbps channel speed.
