The Internet Assigned Numbers Authority (IANA) documents port numbers. They should be your fist stop for questions of this sort. Then you would need to do more reseach on the protocol once you learn what it is. Their Web site is here:
http://www.iana.org/numbers.html Go to P and then Port Numbers and you'll find this: h323hostcall 1720/tcp h323hostcall H.323 is an ITU standard. Here's a URL to some stuff from ITU: http://www.itu.int/rec/recommendation.asp?type=folders&lang=e&parent=T-REC-H.323 The International Multimedia Telecommunications Consortium (IMTC) is also involved in H.323. They have a page about H.323 here: http://www.imtc.org/h323.htm There's more stuff here too: http://www.h323forum.org/ And if you really want something useful, I recommend "Integrating Voice and Data Networks," Scott Keagy, Cisco Press. Keagy says that TCP port 1720 is used by an endpoint learning the destination network address and Transport Service Access Point (TSAP) identifiers for the different layers of H.323 communications. It's one of many ways and endpoint can learn this. It's very complicated. Wish I could say more, but I'm still trying to take it all in too. Priscilla Cisco Nuts wrote: > > Hello,Could someone explain what port 1720 is used for in terms > of voice?Ex. > access-list 199 permit tcp any any eq 1720 access-list 199 > permit tcp any > eq 1720 any Thanks.Sincerely,CN > > ------------------------------------------------------------------------ > > MSN 8 helps ELIMINATE E-MAIL VIRUSES. Get 2 months FREE*. > > Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=64270&t=64267 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
