Network Technical Reference - ZyXEL Communications X6004 User Manual

Table 28 Configuration > PBX > Server Configuration > Server > E-Mail
LABEL
SMTP
Authentication
Apply
Reset

6.10 Network Technical Reference

This section contains background material relevant to the Server screens.
ISDN Overview
ISDN (Integrated Service Digital Network) is a circuit-switched telephone network system. In
ISDN, there are two types of channels: B-channels and D-channels. ISDN allows digital
transmission of voice, video and data over ordinary telephone copper wires using B-channels
with 64 kbps bandwidth. D-channels are mainly used for signaling and control with 16 kbps or
64 kbps bandwidth depending on service levels.
There are two service levels in ISDN as follows.
• BRI (Basic Rate Interface): BRI contains two 64 kbps B channel and one 16 kbps D
channel (2B+1D). A BRI user can have up to 128 kbps service.
• PRI (Primary Rate Interface):
• North America and Japan use 23B+1D, with a total bandwidth of 1.544 Mbps (T1).
• Europe, Australia and most of the rest of the world use the slightly higher capacity E1
which is 30B+1D with a total bandwidth of 2.048 Mbps.
X6004 User's Guide
DESCRIPTION
Select this and enter your username and password if user authentication is
required in the mail server.
Click this to save your changes.
Click this to set every field in this screen to its last-saved value.
Chapter 6 Server
129