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This video explains the phases of the T.30 fax protocol.

Hello my name is Jay Campbell with The Fax Guys for RightFax University.

This video explains the phases of the T.30 fax protocol.

This video was recorded at 1280 by 720 resolution for High Definition and is best viewed in full screen mode.

The T.30 protocol is the International Telecommunications Unit standard for fax transmission.

The T.30 protocol specifies the procedures and capabilities that sending and receiving terminals use to set up a fax call, determine the image size, encoding, and transfer speed to be used during the call, establish the location of page breaks, and terminate the call.

Understanding the phases of the fax transmission can aid greatly in troubleshooting transmission and reception problems.

Phase A - Call Establishment
Sender dials the receiver and begins transmitting fax announce tone. Receiver recognizes this and sends fax answer tone. Sender recognizes announce tone and begins Phase B.

Phase B - Handshaking
Sender and Receiver negotiate capabilities. Once the handshake is established, message transmission can occur.

Phase C - Message Transmission
Data transmission speed established. Sender sends image data.

Phase D - Post Message Procedure After the image data is sent, the sender transmits an end-of-procedure signal. The receiver acknowledges the end of the transmission, and confirms that the pages have been received successfully.

Phase E - Call Release The sender sends a disconnect code to the receiver. Both sender and receiver disconnect from the line. At this point, another transmission can occur starting at Phase A.

As you can see undersanding when and where a fax transmission is failing within this model can greatly aid in pinpointing the cause and resolution of the failures.

This is Jay Campbell with The Fax Guys for RightFax University saying thank you for watching and Please visit us again. The RightFax University is a work under continual progress and we update often.