December 2, 2006 KTTCP 4

### NAME

kttcp - kernel support for testing network throughput

### SYNOPSIS

pseudo-device kttcp

### DESCRIPTION

This driver provides kernel support for testing network throughput from the perspective of the kernel. It is similar in spirit to the classic ttcp network benchmark program, the main difference being that with kttcp, the kernel is the source and sink of the data.

Testing like this is useful for a few reasons:

1. This allows us to know what kind of performance we can expect from network applications that run in the kernel space, such as the NFS server or the NFS client. These applications don't have to move the data to/from userspace, and so benchmark programs which run in userspace don't give us an accurate model.

2. Since data received is just thrown away, the receiver is very fast. This can provide better exercise for the sender at the other end.

3. Since the NetBSD kernel currently uses a run-to-completion scheduling model, kttcp provides a benchmark model where preemption of the benchmark program is not an issue.

### SEE ALSO

```pkgsrc/benchmarks/kttcp`, ```pkgsrc/benchmarks/ttcp`