Transmit TEP Operations

Transmit TEP ACKs

A transmit TEP shall not send an ACK packet.

Transmit TEP Sequence Number Allocation

Each DATA packet transmitted shall have a sequence number allocated from the TEP’s transmit window range of available sequence numbers.

CONTROL Packet Sequence Number

All CONTROL packets shall be transmitted with a sequence number of zero.

Transmit Window

A transmit TEP shall maintain a sliding window range of consecutive sequence numbers that are available for transmitting DATA packets.

Unacknowledged Packets

The transmit window shall limit the number of unacknowledged DATA packets that can be transmitted and prevents transmit operations of DATA packets outside the sliding window until the ACK packet corresponding to the first DATA packet in the window has been received. This process effectively throttles transmit operations.

Transmit Window Start

The transmit window start shall be set to 1 when a CONTROL packet’s ACK is received.

Transmit Window Advance

The transmit window start shall be advanced by 1 when the ACK is received for the first sequence number in the transmit window.

Packet Retransmit

A transmitted DATA packet that is not acknowledged within a channel specific timeout interval shall be retransmitted with the original sequence number up to a channel specific number of times.

Retry CONTROL

When a channel specific number of retry attempts have been exceeded the channel shall be reset.

Timeout Start

The timeout interval shall begin when the last byte of the DATA or CONTROL packet has been transmitted.

URGENT Packet Transmission (If Implemented)

URGENT packets shall be sent immediately without being allocated a transmit window sequence number or starting an acknowledgement timer.

Note: URGENT packets are sent once without retires or acknowledgements.