I want to test ISDN throughput between 2 x 2600 routers and TTCP looks like a useful tool. I have each router running the same IOS version, but one of them doesn't respond to a "TTCP" command; aaa#ttcp Translating "ttcp" Translating "ttcp" % Unknown command or computer name, or unable to find computer address aaa#show ver Cisco Internetwork Operating System Software IOS (tm) C2600 Software (C2600-DS-M), Version 12.1(19), RELEASE SOFTWARE (fc1) Copyright (c) 1986-2003 by cisco Systems, Inc. Compiled Tue 04-Mar-03 07:53 by kellythw Image text-base: 0x80008088, data-base: 0x80E14C9C ROM: System Bootstrap, Version 11.3(2)XA4, RELEASE SOFTWARE (fc1) aaa uptime is 26 minutes System returned to ROM by power-on System image file is "flash:c2600-ds-mz.121-19.bin" cisco 2610 (MPC860) processor (revision 0x203) with 28672K/4096K bytes of memory .. Processor board ID JAD05081021 (2143539888) aaa# bbb# bbb#show ver Cisco Internetwork Operating System Software IOS (tm) C2600 Software (C2600-JK2S-M), Version 12.1(19), RELEASE SOFTWARE (fc1) Copyright (c) 1986-2003 by cisco Systems, Inc. Compiled Tue 04-Mar-03 08:15 by kellythw Image text-base: 0x80008088, data-base: 0x81110DD4 ROM: System Bootstrap, Version 11.3(2)XA4, RELEASE SOFTWARE (fc1) bbb uptime is 6 minutes System returned to ROM by power-on System image file is "flash:c2600-jk2s-mz.121-19.bin" cisco 2610 (MPC860) processor (revision 0x203) with 45056K/4096K bytes of memory .. Processor board ID JAD052309AK (3064794459) M860 processor: part number 0, mask 49 Bridging software. 32K bytes of non-volatile configuration memory. 16384K bytes of processor board System flash (Read/Write) Configuration register is 0x2102 bbb#ttcp transmit or receive [receive]: bbb# ****************8 So , any ideas why AAA doesn't respond? Also can I abort a TTCP session with Ctrl/C or similar - It looks as though when you are ready to receive you must reboot the router to get the IOS prompt back. TIA< Ned