Compression Control Protocol (Ccp); Multilink Ppp - ZyXEL Communications omni TA128 User Manual

ATS87.2 = 1 - Accept PAP/None only.
ATS87.2 = 0 - Accept CHAP/PAP/None (default).

Compression Control Protocol (CCP)

The ISDN channel can be utilized more effectively when using
compression. Compression Control Protocol (CCP) is used by PPP
to negotiate compression methods between peers. CCP starts after
the PPP reaches the network phase. Both ends must support the
same compression method to start packet compression. ZyXEL
supports STAC/LZS. Right now STAC/LZS is only supported with
single history check mode 0 (none), 3 (sequence) and 4 (extended).
Mode 1 (LCB) and mode 2 (CRC) are not supported due to patent
limitations. CCP negotiation is described in RFC1962. STAC/LZS
is described in RFC1974. The TA will monitor the DTE's activity.
If software compression has been negotiated, the TA will
automatically disable STAC/LZS compression.
Related commands:
AT&K00 - Disable CCP negotiation (default).
AT&K44 - Enable CCP negotiation.

Multilink PPP

There are two B channels in basic rate ISDN. This offers the
possibility of opening multiple simultaneous channels between
systems giving users additional bandwidth on demand. Multilink
PPP is a method for bundling both B channel into one PPP link for
higher throughput. It must be negotiated in the link establish phase
by both peers. If Multilink PPP is negotiated successfully, the
second link will be dialed after the first link reach network phase. In
some countries the directory number is not the same for both
channels. For dialing the second B channel with a different
directory number, both numbers must be obtained before dialing
out unless the peer supports BACP/BAP, which will be described
later in this chapter. Multilink PPP is described in RFC1990.
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