3.8 Dynamic Routing and Its Relation to Other Routing
In the case of dynamic routing in the telephone network, the critical constraint is that the path must have at least one unit of bandwidth available to be able to route a call. This is really the idea of a constraint.
| Furthermore, trunk reservation is a form of constraint since it is preferable to have it to maintain the stability of the network. As in RTNR, sometimes it is not preferable to have certain switches on the routing path. Thus, in essence, alternate route selection in dynamic routing requires taking into consideration constraints such as availability of bandwidth on a path, any restriction due to trunk reservation, switch preference, and so on. Table 3.1 shows comparison between intradomain link state-based routing in IP networks and dynamic routing in telephone networks. |
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