
9
CONFIGURING PPP, MLPPP, AND
HDLC
9.1Layer Two Configurations: PPP, MLPPP, and
HDLC
Black Box systems may be configured for a variety of Layer 2 protocols. This document outlines
Black Box LR1104A systems are often used at POPs to aggregate data for WAN transmission. The following figure details PPP and multilink PPP connections from two CPE sites to a main site.
Figure 17 PPP/MLPPP Application
LR1114A
SITE 1
4 x T1 | LR1104A | |
(MLPPP) | ||
|
CT3
WAN
Router/DSU
SITE 2
Site 1 uses a Black Box LR1114A system to establish a 6 Mbps MLPPP connection (four T1 lines) to the main site. In this example, MLPPP segmentation is configured lower than the default setting of 512 bytes, and the differential delay tolerance is tighter than the default 128 milliseconds.
Site 2 connects to the main site over a single T1 link with PPP encapsulation. The LR1104A system PPP parameters (i.e., the maximum transmit and receive byte sizes) are adjusted to comply with the Site 1 router configuration.