There's a shroud of mystery around protocol port mappings. It's
documented one way, taught another, but no one really knows what the
proctor is looking for. To me, the definitive answer would be to look
at the open ports on servers ("netstat -a" from CMD), and the open ports
on the routers ("sh ip sockets"). This will show the exact ports being
used by the active devices, including src/dst and udp/tcp (IP 17 and 6
respectively); however, this may not be what the proctor is looking for.
For example, if you're using UDP for SIP, there will not be an open TCP
port. If the proctor sees that you've only included udp 5060 for SIP,
he may deduct points. For something like this, there should be a right
way; otherwise, we should be able to just remember the port numbers and
use tcp/udp src/dst for all signaling traffic. It doesn't make sense to
me that we can be overkill with some, but not with others. Since my lab
is next week, I'm going to just memorize it per IPExpert and hope for
the best, instead of trying to make sense of it. I think it's worth
bringing up to the proctors though.
Anyone have any thoughts or suggestions on this?
Greg Jost
Network Consulting Engineer
Unified Communications Practice
Cisco Systems, Inc.
214-274-1922
