For every entity (and associated store and forward machine) a message touched in its path to delivery is regarded as a hop. The count starts from when the enterprise submits the message to a network and stops before the final terminating operator SMSC. e.g. Acme, Inc. sends a message to an AT&T subscriber via the CLX network and CLX sends the message to AT&T for On-Net delivery, this would be regarded as One-Hop. To illustrate a multi-hop, if Acme, Inc. needs to send a message to an AT&T subscriber, but has to use an intermediary service, like SMSAGG, Inc. and SMSAGG sends the message to CLX for delivery, then this would make it two hops. If CLX uses its own SMSCs for delivery then this would be a Zero-Hop connection. In general, the less hops the better, as each hop takes time and can potentially have latency and security vulnerabilities.
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