Measuring Latency on IOS Routers
Have you ever needed to measure the latency between two routers on your network and needed a tool that could provide the statistics to you? Look no further than your very own IOS router. Since IOS 11.2, Cisco routers have a built-in Test TCP utility (TTCP) that can allow you to measure TCP throughput through an IP Path. To use it, start the receiver on one side of the path, then start the transmitter on the other side. The transmitting side sends a specified number of TCP packets to the receiving side. At the end of the test, the two sides display the number of bytes transmitted and the time elapsed for the packets to pass from one end to the other. You can then use these figures to calculate the actual throughput on the link. A detailed sample usage guide can be found at the following location:
http://www.cisco.com/warp/public/471/ttcp.html