ZyXEL Communications ACCESSING INTERNET & INTRANET omni series - Manual (Page 77)

X.75 ISDN Communications 65
10
X.75 ISDN
Communications
This chapter will describe how to set-up and configure your TA with
X.75 protocol. The table below shows the specifications of different
ISDN protocols:
V.110 V.120 X.75
Layer 1 80 Bits
Framing HDLC HDLC
Layer 2 None LAPD LAPB
Transparent
Layer 3 None V.120 ISO8208T.70 NL
Error Control No Yes Yes
V.42bis No Yes Yes
Async or Sync
if used with
V-Series DTE Async Only Async
Only Async Only
Bundle No Yes Yes
Max. Line
Speed Async: 38.4
Kbps 64Kbps
128Kbps 64Kbps
128Kbps
AT-Command
Configuration ATB10 ATB20 ATB00
Transparent
ATB01: T.70 NL
X.75 was originally designed for packet-switched signaling systems
in public networks to provide data transmission services. But it is
now also used as the link layer for telematic services (as defined in
T.90) in ISDN. These services include both ISDN circuit-switched
mode (DTE-DTE communication) and ISDN packet-switched mode
(DTE-DCE communication).