 - NAK is an abbreviation for negative acknowledgment or not acknowledged. It is a signal used in digital communications to ensure that data is received with a minimum of errors. Sometimes the NAK signal is called REJ (for rejection or rejected). An alternative signal is ARQ (automatic request for retransmission).
The NAK, REJ, or ARQ signal is typically sent by the recipient of a message (destination) back to the sender (source) after the receipt of an unrecognizable block of data of specific size. When the source receives a NAK or REJ signal from the destination, the source either repeats the block of data until the destination station recognizes the protocol and responds with an ACK (acknowledgment or acknowledged) signal, or else stops transmission entirely. When the source receives an ARQ signal from the destination, the source retransmits the block of data.
NAK, REJ, or ARQ signals are special ASCII characters reserved so they are not confused with data characters.
Compare ACK.
 |
Learn more about Network Administration |
| Networking FAQ: These FAQs for networking will help you learn networking basics. |
| Network user management: Use this guide to learn how to manage problem users on your network -- from un-savvy Internet novices to toxic bosses -- to keep your network secure. |
| Troubleshooting -- 'Network Know-How' Chapter 17: Troubleshooting, Chapter 17 of 'Network Know-How,' shows tools and methods that identify and solve network problems. Use this chapter as a tutorial to fixing computer connections. |
| Network management frameworks: FCAPS and ITIL: Network management is a complex topic. Thus far, two frameworks exist that can be of some use for understanding and taming network management: FCAPS and ITIL. |
| Networking podcasts: Listen to our networking podcasts and learn more about technologies you need to know to keep your network running smoothly. |
| The IT Guy: Networking comics: In our networking comic series, the IT guy and his office coworkers encounter day-to-day network challenges. |
| CONTRIBUTORS: |
Quinn Carver |
| LAST UPDATED: |
13 Apr 2007
|
 |
Do you have something to add to this definition? Let us know.
Send your comments to techterms@whatis.com
|
 |
 |
| |
RELATED GLOSSARY TERMS
| Terms from Whatis.com − the technology online dictionary |
 |
availability
(SearchNetworking.com)
1) In a telephone circuit, availability is the ratio between the time during which the circuit is operational and elapsed time.
2) In a network...
|
|
carrier detect
(SearchNetworking.com)
|
|
|
Show me everything on 