deploying and managing ip over wdm networks - Index of

248 Deploying and Managing IP over WDM Networks
GRANULARITY
Packet
Burst
Circuit
Circuit-switched
static
Static
X
FLEXIBILITY
Circuit-switched
dynamic
Dynamic
X
X
X
Burst-switched
optical domain will in the future become adaptable to the specific
needs. Next to providing huge bandwidth lightpipes (circuit switching),
finer switching granularities will be available as envisaged in optical
burst and in optical packet switching. Switching packets optically is
said to combine the advantages of statistical multiplexing and optically
transiting a node (in order to avoid expensive, high-speed O/E/O
conversions).
Figure 13.4 maps some of the IST projects working on photonic networking
with respect to the evolution scenario depicted here.
13.2.2 The Global Communication Network in More Detail
Packet-switched
Time
Figure 13.3 Evolution in the flexibility and in the switching granularity of the OTN.
When looking into the ION in a more detailed geographical way, we can define
several parts of the network as illustrated in Figure 13.5, each with its specific
characteristics, requirements, and technological trends.
The OPTIMIST consortium tried to outline some facts and figures for
these several levels of the global communication network. Please note that the
medium-term scenario depicts a time frame of 5 to 10 years from now; the
long-term scenario looks to the possible network characteristics 10 to 20 years
from now.
• The global area network (GAN), involving mainly the undersea connections,
needs to provide very large connection distances without