Call Routing While One Call Is Already Connected; Understanding Multilink Ppp And Bacp/Bap; What Is Multilink Ppp; What Is Bacp/Bap - 3Com 3C892 - OfficeConnect ISDN Lan Modem Router User Manual

Understanding
Multilink PPP and
BACP/BAP
Rob's PC
192.168.1.2
Laura's PC
192.168.1.3
Buddy's PC
192.168.1.4
Sally's PC
192.168.1.5
Figure 9 IP Address Translation

Call Routing While One Call Is Already Connected

If the ISDN LAN Modem has established a call to a remote destination, for
instance, to an ISP, and the ISDN LAN Modem receives more packets, then the
ISDN LAN Modem looks at the Network ID of the packets for proper routing. For
example, if the Network ID of the packets matches that of the remote LAN and
that connection has not yet been established, then the call is placed and the
connection is made. If the Network ID does not match and the call type is an
Internet access call, then the packets are routed to the ISP.
Note that the ISDN LAN Modem always calls the first configured ISP. If you have
configured a second ISP and want to use that one instead, from the ISDN LAN
Modem's configuration home page go to Workstation Parameters, select your
computer, and then associate only the ISP that you want to use.

What is Multilink PPP?

Multilink PPP is a protocol which combines multiple point-to-point protocol (PPP)
connections to form a single high-bandwidth channel. With a BRI line, Multilink
PPP combines the two 56 Kbps or 64 Kbps ISDN B channels, creating a virtual,
single connection of up to 112 Kbps or 128 Kbps.

What is BACP/BAP?

BACP/BAP is used in conjunction with the Multilink PPP feature and is transparent
to the user (that is, it will not be visible to you as it occurs in the background). You
need not configure this functionality. When Multilink PPP is negotiated, the
Bandwidth Allocation Control Protocol (BACP) negotiates with the peer
equipment to determine whether the peer supports BAP. If the peer supports BAP

Understanding Multilink PPP and BACP/BAP

Translates PC IP
IP address
addresses to IP
assigned by ISP
address assigned
by ISP
198.6.1.1
LAN STATUS
3 Com
OfficeConnect™
1
Alert PWR ISDN B1 B2 Tx Coll 2 3 4 ISDN LAN Modem
OfficeConnect ® ISDN LAN Modem
192.168.1.1
ISDN BRI line
Internet/Intranet or
online service
ISDN BRI line
Public telephone
network
21