User`s manual

Data Options and Profiles
packet switched data service for Mode DX25 and ISDN B-channel circuit
switched data service for the other Modes).
B2 An abbreviation for B-channel Mode 2, configures the ADM for
establishment of outgoing data calls using AT&T’s Mode 2 circuit switched
data transmission protocol. B2 and BA are appropriate selections for
circuit switched connections over 64 kbps facilities to endpoints supporting
one or both of these protocols. Mode 2 protocol is not error corrected and
does not provide bidirectional flow control when endpoint speeds are
mismatched. Mode 2 does provide less delay than Mode 3 on transmitted
and received data. Select B2 to establish a data call using Mode 2
protocol. If the user escapes to Local Mode while the far end is
transmitting Mode 2 data, this data may be lost.
BA An abbreviation for B-channel Adaptive, configures the ADM for
establishment of outgoing data calls using AT&T’s Mode 3/2 adaptive
circuit switched data transmission protocol. B2 and BA are appropriate
selections for circuit switched connections over 64 kbps facilities to
endpoints supporting one or both of these protocols. Mode 3 protocol is
error corrected and does provide bidirectional flow control when endpoint
speeds are mismatched. Mode 3 can cause slightly higher delays than
Mode 2 on transmitted and received data. Mode 3 is a packet-oriented
protocol and uses the Packet Assembler Disassembler (PAD) data
options. Select BA to attempt to establish a data call using AT&T Mode 3
protocol. If the endpoint you are calling cannot accept this type of call, the
ADM then reattempts using AT&T Mode 2 protocol.
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