User Guide
Page 38
...to detect the speed of your device's key features. ZyXEL Devices which work over ISDN do not support Annex M. Models with "1" or "7" as the next to the last character (like the P-2602HWL-D1A or the P-2602HWL-D7A) denote a device that works over ISDN (Integrated Services...-in either a crossover or straight-through Ethernet cable. P-2602H(W)(L)-DxA Series User's Guide Models with "3" as the next to the last character (like the P-2602HWL-D3A) denote a device that works over T-ISDN (UR-2). Note: Only use firmware for each standard are from your ZyXEL Device's specific model.
...to detect the speed of your device's key features. ZyXEL Devices which work over ISDN do not support Annex M. Models with "1" or "7" as the next to the last character (like the P-2602HWL-D1A or the P-2602HWL-D7A) denote a device that works over ISDN (Integrated Services...-in either a crossover or straight-through Ethernet cable. P-2602H(W)(L)-DxA Series User's Guide Models with "3" as the next to the last character (like the P-2602HWL-D3A) denote a device that works over T-ISDN (UR-2). Note: Only use firmware for each standard are from your ZyXEL Device's specific model.