Module consts 

DPlus wire-format constants.

Every magic byte and every duration here is annotated with the exact line in the GPL reference implementation it was derived from.

Constants

CONNECT_RETX

Number of times the initial connect packet is retransmitted.

DEFAULT_PORT

Default UDP port for DPlus (REF) reflectors.

DISCONNECT_RETX

Number of times the unlink packet is retransmitted.

DISCONNECT_TIMEOUT

DPlus disconnect ACK timeout — give up waiting for unlink reply.

DSVT_MAGIC

DSVT magic at offsets [2..6] of every voice header / voice data / EOT packet.

DSVT_TYPE

DSVT type byte (offset 1 of every DSVT-framed packet).

DV_CLIENT_ID

DV019999 8-byte client identifier embedded in LINK2 at offsets [20..28].

HEADER_RETX

Number of times the voice header is retransmitted.

KEEPALIVE_INACTIVITY_TIMEOUT

DPlus outgoing keepalive inactivity timeout.

KEEPALIVE_INTERVAL

DPlus keepalive interval.

LINK1_ACK_BYTES

LINK1 ACK echo — server replies with the same bytes as LINK1.

LINK1_BYTES

LINK1 connect packet (5 bytes).

LINK2_ACCEPT_TAG

LINK2 reply tag for accept (4 bytes at offsets [4..8] of an 8-byte reply).

LINK2_BUSY_TAG

LINK2 reply tag for busy (4 bytes at offsets [4..8] of an 8-byte reply).

LINK2_HEADER

LINK2 packet header (4 bytes; full packet is 28 bytes with callsign + DV019999).

LINK2_REPLY_PREFIX

LINK2 reply prefix (first 4 bytes of an 8-byte reply, before the tag).

POLL_BYTES

Keepalive poll packet (3 bytes).

POLL_ECHO_BYTES

Poll echo — server replies with the same bytes as POLL.

RETX_DELAY

Inter-copy delay for retransmission bursts.

UNLINK_ACK_BYTES

UNLINK ACK echo — server replies with the same bytes as UNLINK.

UNLINK_BYTES

UNLINK packet (5 bytes).

VOICE_DATA_PREFIX

Voice data DSVT length byte (offset 0 of a voice data packet).

VOICE_EOT_PREFIX

Voice EOT DSVT length byte (offset 0 of an EOT packet).

VOICE_EOT_TRAILER

EOT trailing pattern (last 6 bytes of an EOT packet).

VOICE_HEADER_PREFIX

Voice header DSVT length byte (offset 0 of a voice header packet).

VOICE_INACTIVITY_TIMEOUT

DPlus voice inactivity timeout — synthesize VoiceEnd after this.