Bandwidth and
Latency

Distributed applications take advantage of a network to tie components together. In theory, DCOM completely hides the fact that components are running on different computers. In practice however, applications need to consider the two primary constraints of a network connection:

• Bandwidth: the size of the parameters passed into a method call directly affects the time it takes to complete the call.
• Latency: the physical distance and the number of network elements involved (such as routers and communication lines) delay even the smallest data packet significantly. In the case of a global network like the Internet, these delays can be on the order of seconds.

How does DCOM help applications to deal with these constraints? DCOM itself minimizes network round trips wherever possible to avoid the impact of network latency. DCOM's preferred transport protocol is the connectionless UDP subset of the TCP/IP protocol suite: The connectionless nature of this protocol allows DCOM to perform several optimizations by merging many low-level acknowledge packages with actual data and pinging messages. Even running over connection-oriented protocols, DCOM still offers significant advantages over application-specific custom protocols.