ibps-so 2016 · Question 40 of 394

Two systems supplied by two di erent vendors are to exchange the bank's daily position le. The rst will not read what the second writes. On investigation it emerges that the two disagree upon the order of the elds in the record and upon the width of the length indicator, upon what is to be understood by a particular value in the control eld, and upon how long the sender may wait before it concludes that no acknowledgement is coming. The architect has told the vendors that these three disagreements are precisely the three matters that any protocol exists to settle, and that until they are settled no amount of correct wiring will make the two systems communicate. In data communication, a protocol is correctly described as:

1. AA physical path along which the data travels between the two entities, together with the connectors at either end of it
2. BA program that converts a message from the format used by one application into the format used by another
3. CA set of rules governing the exchange of data between two entities, xing the syntax (the format and encoding of the message), the semantics (the meaning of each eld and the action it calls for) and the timing (when a message may be sent and how fast)Correct
4. DA device that joins two networks and forwards tra c between them upon the basis of an address
5. EA schedule of charges levied by the carrier for the transport of data between two stated points