In fiber optics, a ray that passes through the optical axis of an optical fiber (in contrast with a skew ray, which does not).

See network topology.

See network topology.

The relationship between two signals such that their corresponding significant instants occur at the same average rate.

1. Any thought or idea expressed briefly in a plain or secret language, prepared in a form suitable for transmission by any means of communication. [JP 1-02]
Note: A message may be a one-unit message or a multiunit message.
2. [In telecommunications,] Record information expressed in plain or encrypted language and prepared in a format specified for intended transmission by… (Read More →)

In a signal message, data transmitted between the user part and the message transfer part to identify the boundaries of the signal message.

Determining that a message has not been changed since leaving its point of transmission, where: (a) the identity of the originator is verified, and (b) the source, uniqueness, and integrity of the message are verified. [After X9.49]

1. A bit string that is a function of both data (either plaintext or ciphertext) and a secret key, and that is attached to the data in order to allow data authentication.
Note: The function used to generate the message authentication code must be a one-way function. [2382-pt.8]
2. Data associated with an authenticated message allowing a receiver to verify… (Read More →)

1. For the single message format, the message words.
2. For the multiple message format, the parameter messages. [After T1.401-1998]

An electronic-mail conference capability using data terminals.
Note: Control can be maintained by the user or by the network.