The simplest way I know of to explain these is to take the last letter (O or S) and associate that to where it will connect TO. So, an FXO connects to an Office (PBX or CO) and an FXS connects to a Station device (Telephone, Fax, or answering machine). As Chuck suggests, if you are connecting from an "O" it will connect to an "S", and vice versa, just like DTE and DCE. (Remembering it this way comes in handy when you are connecting two PBXs, or PBX to CO, or voice gateway to PBX or CO). OBTW, that voice gateway is a microscopic size PBX. Bruce
Chuck's Long Road wrote: I did some quick looks into a couple of books I have to see what they say. Scott Keagy's book "Integrating Voice and Data Networks" has nothing to say about FXO and FXS in particular. The "Cisco Call Manager Fundamentals" book makes the rather brief assertion that "FXS ports provide connection to loop-start or ground-start telephone lines, ... ( PBX ) ports, and other analogue telephone devices. FXO ports provide connection to central office ports or PBX extensions" Interesting wording, and seems to apply to what I was told. Learn something new, some better way to think about things, every day. Chuck ""Jennifer Mellone"" wrote in message [EMAIL PROTECTED]">news:[EMAIL PROTECTED] ... That sounds great and makes more sense now! I always like reading your posts :-) I always confuse which device plugs into which port. I remember it like this: Plug phone or "Station" into FXS (where Station=S) Plug PBX/CO into FXO (where Office=0) - Jennifer -- Bruce Enders Email: [EMAIL PROTECTED] Chesapeake NetCraftsmen o:(410)-757-3050, c:(443)-994-0678 1290 Bay Dale Drive, Suite 312 WWW: http://www.netcraftsmen.net Arnold, MD 21012-2325 Cisco CCSI# 96047 Efax 443-331-0651 Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=54352&t=54331 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
