Robert,
I haven't ever measured it (currently all of our RS boxes have on-box SQL) so not sure I even could.  However, maybe you could extract this using a SQL Profiler trace, or possibly even with Perfmon.  or...maybe some network activity logging tool like Ethereal.  Finally, there may be one of the SysInternals tools (http://technet.microsoft.com/en-us/sysinternals/de...) out there that will get you what you're looking for.  I checked the Networking sub-section and didn't see anything.  There may be something in ProcessExplorer that would capture that (it does just about everything else!).