Cisco VG224 Hardware Installation Guide - Page 70

Analog Voice Multiport Pinouts (RJ-21X/CA21A) Appendix A Cable Specifications and Information Table A-6 RJ-21 Connector Pinouts Port Connector Pin Number Number 12 12 37 - - Signal Ring Tip - Port Connector Pin Number Number 24 24 49 - 25, 50, 51, 52 Signal Ring Tip GND EIA/TIA-232 Connections The EIA/TIA-232 standard supports unbalanced circuits at signal speeds up to 64 kbps. For connection to a Cisco VG224 voice gateway serial port, use the EIA/TIA-232 serial transition cable with the Cisco 12-in-1 connector on one end and a DB-25 connector (as shown in Figure A-7) on the other. The DB-25 connector can be male for DTE or female for DCE. To order a cable, see the "Obtaining Technical Assistance" section on page 16. Figure A-7 EIA/TIA-232 Serial Transition Cable Connectors DTE 194831 DCE EIA/TIA-449 Connections The EIA/TIA-449 standard, which supports balanced and unbalanced transmissions, is a faster (up to 2 Mbps) version of the EIA/TIA-232 standard that provides more functions and supports transmission over greater distances. The EIA/TIA-449 standard was intended to replace the EIA/TIA-232 standard. However, this standard was not widely adopted because of the large installed base of DB-25 hardware. Also, the larger size of the 37-pin EIA/TIA-449 connectors limited the number of connections possible (fewer than are possible with the smaller, 25-pin EIA/TIA-232 connector). To make a connection to a Cisco VG224 voice gateway serial port, use the EIA/TIA-449 serial transition cable with the Cisco 12-in-1 connector on one end and a DB-37 connector (as shown in Figure A-8) on the other. The DB-37 connector can be male for DTE or female for DCE. To order a cable, see the "Obtaining Technical Assistance" section on page 16. Figure A-8 EIA/TIA-449 Serial Transition Cable Connectors DTE DCE 194832 Cisco VG224 Voice Gateway Hardware Installation Guide A-8 OL-5006-04