3Com SuperStack II User Manual

Also see for SuperStack II: User guide Using User guide User guide Supplement sheet

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3Com SuperStack II User Manual Manual pdf 78 page image

78 APPENDIX A: PROVISIONING YOUR ISDN LINEn The SPID numbers must be unique. The 2-digit TID can be any numberfrom 0 to 62. The TID has no effect on the operation of theSuperStack II bridge/router, but it is a necessary part of the SPID thatthe bridge/router uses to gain access to the ISDN network.n If you request ISDN service from a Northern Telecom DMS-100 serviceprovider, the format is:Area code + 7-digit telephone number + 0 to 8 digit suffix + 2 digitTID.n The TID can be any number from 0 to 62, but needs to be unique sothat the SPIDs are also unique. This format applies when the switch isrunning Custom and NI-1 (North American 3) versions of software.n If you order AT&T 5ESS Custom ISDN services, choose either a Type Aor Type E terminal. The Type E terminal is preferable because it is fordata only.n Do not request supplementary services, such as autohold orconference, because a SuperStack II bridge/router does not supportthem.NT1s and PowerSuppliesThe models 43x and 53x bridge/routers do not come with an NT1. NorthAmerican telephone companies require an NT1 and a power supply forevery ISDN line. Your service provider or telephone company can provideyou with an NT1 and power supply for a small monthly fee. However, youmay prefer to purchase it from an ISDN equipment vendor. The NT1 andpower supply may come in a single, standalone box or the two may be inseparate units. In this discussion, the two units together are referred to asan NT1.The model 44x and model 54x bridge/routers have an integrated NT1.Telephone companies in North America use two kinds of NT1s,differentiated by the data encoding scheme used in transmitting databetween the NT1 and the telephone company’s equipment. The two dataencoding schemes are 2B1Q (two bits mapped into one quaternarysymbol) and alternate mark inversion (AMI). The 2B1Q scheme is thedominant method in use today. The AMI scheme is older and rarely used.HWBook Page 78 Friday, June 19, 1998 3:42 PM