Page 263 - Optical Switching And Networking Handbook

11_200023_CH10/Bates 1/17/01 9:06 AM Page 248

248 Chapter 10

depend on the ability to change quickly, adapt with limited modifi-
cation, and prepare new offerings in the photonic world instead of
the electrical world. These new systems must address open systems
interfaces with the following:

ATM
Plesiochronous Digital Hierarchy (PDH)
SONET/SDH
Digital Signal-level n (DS-n), for example, DS-1, DS-3, and so on.

Each of the services above must be dealt with transparently in
order to achieve acceptance and openness in the carrier communi-
ties. That transparency will be passed along to the end-user (con-
sumer) in a mix of new service offerings where bandwidth will not be
an issue. Instead, the bandwidth will become the underlying trans-
port that no one really worries about, but it is assumed that it will be
there, it will be reliable, and it will be affordable. Without achieving
these parameters, the systems will fail to deliver upon the promises
of the past.
Using the DWDM architectures, the migration and provisioning of
the networks will help keep in mind the need to expand and grow
gracefully. Systems will be required to support the services as shown
in Figure 10-10.
The point of this is not so much that the pipes are bigger. The flow
of the data into these pipes has become dramatically large, thus the
challenges are different.As the data continues to escalate in size and
complexity, the carriers are faced with installing and maintaining
the optical mechanisms to preserve the integrity of the network and

A
Figure 10-10 D
Photonic networks M
OC-3
with DWDM OC-12 A
OC-48 D OPT
M AMP
OPT OPT
AMP AMP

OPT
AMP