Technical information

ADC Telecommunications, Inc.
228 C
HAPTER 10: PACKET OVER SONET ADMINISTRATION
Figure 10-1 shows the POS transport structure in relation to the OSI network
model:
Figure 10-1 Packet Over SONET — Network Structure
POS administration on the Cuda 12000 involves:
■ Administration of the physical SONET interface at layer 1, as described in
“Packet Over SONET (POS) Interface Administration,” next.
■ Administration of the point-to-point protocol (PPP) used to encapsulate
the IP data at layer 2, as described in “Configuring Point-to-Point Protocol
(PPP)” on page 250.
Packet Over SONET (POS) Interface Administration
Packet over Synchronous Optical Network (SONET) allows for high-speed
transport of IP data packets over a SONET STS network. The POS module
contains a single physical interface that supports connection to STS networks
and supports transmission speeds of up to 155 Mbps.
A SONET frame is 810 bytes represented as a grid of 9 rows by 90 columns.
The frame consists of hierarchal layers, each providing services for the layer
above it. Figure 10-2 shows the logical representation of the SONET layers.
IP Datagram
PPP Encapsulation
SONET
Layer 3 — Network Layer
Layer 2 — Data Link Layer
Layer 1 — Physical Transport Layer