3Com 3C10200 NBX Installation Guide - Page 36

36 CHAPTER 1: INTRODUCTION ■ Slow, non symmetric blinking pattern - Waiting for the completion of the binding process to the NCP. Operation: ■ Off for 9 to 10 seconds, on briefly - Idle, the line is not in use. ■ On for 9 to 10 seconds, off briefly - A telephone call is connected on this port. ■ Console Connector - This DB-9 connector provides an RS-232 (DCE) TTY terminal connection for maintenance access. T1 Digital Line Card The optional T1 Digital Line Card lets you connect a T1 line to the NBX system. When configured as standard T1 (DS1), the T1 card supports in-band signaling of 24 DS0 (64 Kbps) "voice" channels and a variety of signaling types and protocols. The T1 carries data at a rate of 1.544 Mbps. When configured as ISDN PRI, the T1 card supports 23 voice channels with PRI services such as Direct Inward Dialing (DID). You must have an external Channel Service Unit (CSU) when you use the 3C10116C T1 Digital Line Card. 3C10116D includes an onboard CSU. The 3C10116D can provide CSU performance statistics, supports loopback testing, and can be configured as a remote device that communicates with its NCP over a routed network. ISDN PRI services require specific circuit provisioning, which you must obtain before you can use the T1 card in PRI mode. See Appendix B for more information. Figure 10 T1 Digital Line Card (3C10116C) T1 3C10116C 3Com NBX Digital Line Card CF RA Nominal LB 10BT UPLINK MDI-X CONSOLE Figure 11 T1 Digital Line Card (3C10116D)