Source IP Port in access-list

[ricey]

This may be a silly question but I'm a little baffled. What is the point of source tcp/ip port numbers on access-lists with the pix. I was under the impression that the requester uses a random high port number to establish a session and the well known port number eg 1352 for Lotus Notes only referred to the port used on the server. In this case how can you allow / block by source port when they are randomly generated.

Thanks for your help.

[mostiguy]

it is just an option. some protocols may use static ports on both ends. you may want to use the range or other keywords to limit the pool of potential ports