arq_protocol.h File Reference

#include <stdbool.h>
#include <stddef.h>
#include <stdint.h>
#include <stdatomic.h>

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Data Structures
struct	arq_frame_hdr_t
struct	arq_mode_timing_t
struct	arq_accept_t

Macros
#define	ARQ_HDR_SUBTYPE_IDX   1
#define	ARQ_HDR_FLAGS_IDX   2
#define	ARQ_HDR_SESSION_IDX   3
#define	ARQ_HDR_SEQ_IDX   4
#define	ARQ_HDR_ACK_IDX   5
#define	ARQ_HDR_SNR_IDX   6
#define	ARQ_HDR_DELAY_IDX   7
#define	ARQ_FRAME_HDR_SIZE   8 /* bytes 0-7 inclusive */
#define	ARQ_CONNECT_SESSION_IDX   1
#define	ARQ_CONNECT_PAYLOAD_IDX   2
#define	ARQ_CONNECT_SESSION_MASK   0x7F
#define	ARQ_CONNECT_ACCEPT_FLAG   0x80
#define	ARQ_CONTROL_FRAME_SIZE   14
#define	ARQ_CONNECT_META_SIZE   2 /* framer byte + connect_meta byte */
#define	ARQ_CONNECT_MAX_ENCODED   (ARQ_CONTROL_FRAME_SIZE - ARQ_CONNECT_META_SIZE)
#define	ARQ_CONNECT_DST_CRC_SIZE   2 /* CRC16-CCITT of DST at bytes [2..3], little-endian */
#define	ARQ_CONNECT_SRC_MAX_ENCODED   (ARQ_CONNECT_MAX_ENCODED - ARQ_CONNECT_DST_CRC_SIZE) /* 10 */
#define	ARQ_CQ_PAYLOAD_IDX   1
#define	ARQ_CQ_SRC_MAX_ENCODED   (ARQ_CONTROL_FRAME_SIZE - ARQ_CQ_PAYLOAD_IDX) /* 13 */
#define	ARQ_BW_TOKEN_NONE   0
#define	ARQ_BW_TOKEN_500   1
#define	ARQ_BW_TOKEN_2300   2
#define	ARQ_BW_TOKEN_2750   3
#define	ARQ_BURST_MAX   5
#define	ARQ_CONTROL_MODE   FREEDV_MODE_DATAC16
#define	ARQ_CHANNEL_GUARD_MS
#define	ARQ_ISS_POST_ACK_GUARD_MS
#define	ARQ_ACCEPT_RX_WINDOW_MS
#define	ARQ_LISTEN_OFF_GRACE_MS   2000
#define	ARQ_CALL_RETRY_SLOTS_DEFAULT   4 /* CALL retries before giving up */
#define	ARQ_CALL_FAST_SLOTS   2
#define	ARQ_ACCEPT_RX_WINDOW_FLOOR_MS   26000
#define	ARQ_ACCEPT_RETRY_SLOTS_DEFAULT   4 /* ACCEPT retries before returning */
#define	ARQ_DISCONNECT_RETRY_SLOTS_DEFAULT   2 /* DISCONNECT frame retries */
#define	ARQ_CALLINT_MIN_S   4.0f
#define	ARQ_CALLINT_DEFAULT_S   0.0f /* 0 = use table default */
#define	ARQ_RETRY_STAGGER_MS_DEFAULT   2000
#define	ARQ_RETRY_STAGGER_MS_MAX   5000
#define	ARQ_CALL_RETRY_SLOTS   atomic_load(&arq_call_retry_slots)
#define	ARQ_ACCEPT_RETRY_SLOTS   atomic_load(&arq_accept_retry_slots)
#define	ARQ_DISCONNECT_RETRY_SLOTS   atomic_load(&arq_disconnect_retry_slots)
#define	ARQ_ACK_DATA_GAP_MS   300
#define	ARQ_CHANNEL_SYNC_HOLD_MS   250
#define	ARQ_CHANNEL_DEFER_MS   500
#define	ARQ_CHANNEL_DEFER_MAX   20 /* ~10 s, then key regardless */
#define	ARQ_REPLY_WINDOW_MARGIN_MS   1000
#define	ARQ_SNR_HYST_DB   5.0f
#define	ARQ_SNR_MIN_DATAC15_DB
#define	ARQ_SNR_MIN_DATAC4_DB
#define	ARQ_SNR_MIN_DATAC3_DB   -1.0f
#define	ARQ_SNR_MIN_DATAC1_DB   3.0f
#define	ARQ_SNR_MIN_DATAC17_DB
#define	ARQ_SNR_MIN_QAM16C2_DB
#define	ARQ_DISCONNECT_DRAIN_TIMEOUT_S_DEFAULT   45
#define	ARQ_DISCONNECT_DRAIN_TIMEOUT_S   atomic_load(&arq_disconnect_drain_timeout_s)
#define	ARQ_CONNECT_VERSION   1
#define	ARQ_CONNECT_EXT_BW_MASK   0x03
#define	ARQ_CONNECT_EXT_VERSION_SHIFT   2
#define	ARQ_CONNECT_EXT_VERSION_MASK   0x0C
#define	ARQ_CONNECT_EXT_CAROUSEL   0x10
#define	ARQ_ACCEPT_CALLED_CRC_IDX   4
#define	ARQ_ACCEPT_NONCE_IDX   6
#define	ARQ_ACCEPT_LEVEL_IDX   8
#define	ARQ_ACCEPT_LEVEL_CTL_DEAF

Enumerations
enum	arq_subtype_t { ARQ_SUBTYPE_DISCONNECT = 4 }

Functions
int	arq_protocol_retry_rank (const char *local_call, const char *remote_call)
uint64_t	arq_protocol_retry_deadline_ms (float seconds, int rank)
int	arq_protocol_encode_hdr (uint8_t *buf, size_t buf_len, const arq_frame_hdr_t *hdr)
	Encode a parsed header into the first ARQ_FRAME_HDR_SIZE bytes of buf.
int	arq_protocol_decode_hdr (const uint8_t *buf, size_t buf_len, arq_frame_hdr_t *hdr)
	Decode the ARQ header from the first bytes of buf.
uint8_t	arq_protocol_bw_token_from_hz (int bw_hz)
	Map a configured bandwidth in Hz to an on-air BW token.
int	arq_protocol_bw_hz_from_token (uint8_t bw_token)
	Map an on-air BW token back to Hz.
uint8_t	arq_protocol_encode_snr (float snr_db)
	Encode a floating-point SNR (dB) into the snr_raw wire byte.
float	arq_protocol_decode_snr (uint8_t snr_raw)
	Decode snr_raw wire byte back to float dB.
const arq_mode_timing_t *	arq_protocol_mode_timing (int freedv_mode)
	Look up mode timing entry for a FreeDV mode.
float	arq_protocol_longest_burst_s (void)
	Longest single-burst airtime across the whole mode table, in seconds.
float	arq_protocol_call_interval_s (void)
	Return the CALL/ACCEPT retry interval in seconds, applying any CALLINT override.
float	arq_protocol_call_interval_for_mode_s (int mode)
uint16_t	arq_protocol_callsign_crc16 (const char *callsign)
	Compute CRC16-CCITT of an uppercase-normalised callsign.
int	arq_protocol_build_disconnect (uint8_t *buf, size_t buf_len, uint8_t session_id, uint8_t snr_raw)
	DISCONNECT frame (PACKET_TYPE_ARQ_CONTROL).
int	arq_protocol_build_call (uint8_t *buf, size_t buf_len, uint8_t session_id, const char *caller, const char *called, int bw_hz)
	Build a CALL.
int	arq_protocol_build_accept (uint8_t *buf, size_t buf_len, uint8_t session_id, const char *called, const char *caller, int bw_hz, int start_level, uint16_t nonce)
	Build an ACCEPT.
bool	arq_protocol_connect_version_ok (const uint8_t *buf, size_t buf_len)
	Is buf a CALL or ACCEPT of this protocol version?
bool	arq_protocol_connect_dst_matches (const uint8_t *buf, const char *callsign)
	Is a CALL or ACCEPT addressed to callsign (bytes 2-3, all 16 bits)?
int	arq_protocol_parse_call (const uint8_t *buf, size_t buf_len, uint8_t *session_id_out, char *caller_out, int *bw_hz_out)
	Parse a CALL: session id, the caller's callsign, the bandwidth.
int	arq_protocol_parse_accept (const uint8_t *buf, size_t buf_len, arq_accept_t *out)
	Parse an ACCEPT.
int	arq_protocol_build_cq (uint8_t *buf, size_t buf_len, const char *src, int bw_hz)
	Build a compact DATAC16 CQ frame carrying source callsign and BW token.
int	arq_protocol_parse_cq (const uint8_t *buf, size_t buf_len, char *src_out, int *bw_hz_out)
	Parse a compact DATAC16 CQ frame.

Variables
_Atomic int	arq_call_retry_slots
_Atomic int	arq_accept_retry_slots
_Atomic int	arq_disconnect_retry_slots
_Atomic float	arq_callint_override_s
_Atomic int	arq_retry_stagger_ms
_Atomic int	arq_disconnect_drain_timeout_s
const arq_mode_timing_t	arq_mode_table []
const int	arq_mode_table_count

Macro Definition Documentation

ARQ_ACCEPT_CALLED_CRC_IDX

#define ARQ_ACCEPT_CALLED_CRC_IDX   4

ARQ_ACCEPT_LEVEL_CTL_DEAF

#define ARQ_ACCEPT_LEVEL_CTL_DEAF

Value:

                                             7   /* the callee hears the caller below
                                             the control mode: start at the floor */

ARQ_ACCEPT_LEVEL_IDX

#define ARQ_ACCEPT_LEVEL_IDX   8

ARQ_ACCEPT_NONCE_IDX

#define ARQ_ACCEPT_NONCE_IDX   6

ARQ_ACCEPT_RETRY_SLOTS

#define ARQ_ACCEPT_RETRY_SLOTS   atomic_load(&arq_accept_retry_slots)

ARQ_ACCEPT_RETRY_SLOTS_DEFAULT

#define ARQ_ACCEPT_RETRY_SLOTS_DEFAULT   4 /* ACCEPT retries before returning */

ARQ_ACCEPT_RX_WINDOW_FLOOR_MS

#define ARQ_ACCEPT_RX_WINDOW_FLOOR_MS   26000

ARQ_ACCEPT_RX_WINDOW_MS

#define ARQ_ACCEPT_RX_WINDOW_MS

Value:

                                            9000  /* ACCEPTING RX window after ACCEPT TX:
                                            * ISS_guard(900)+DATAC15(4400)+margin(3700)
                                            * Old value 7000 left only ~300ms margin
                                            * and raced with TIMER_RETRY, causing
                                            * 3-4 wasted ACCEPT retries (~28s).    */

ARQ_ACK_DATA_GAP_MS

#define ARQ_ACK_DATA_GAP_MS   300

ARQ_BURST_MAX

#define ARQ_BURST_MAX   5

ARQ_BW_TOKEN_2300

#define ARQ_BW_TOKEN_2300   2

ARQ_BW_TOKEN_2750

#define ARQ_BW_TOKEN_2750   3

ARQ_BW_TOKEN_500

#define ARQ_BW_TOKEN_500   1

ARQ_BW_TOKEN_NONE

#define ARQ_BW_TOKEN_NONE   0

ARQ_CALL_FAST_SLOTS

#define ARQ_CALL_FAST_SLOTS   2

ARQ_CALL_RETRY_SLOTS

#define ARQ_CALL_RETRY_SLOTS   atomic_load(&arq_call_retry_slots)

ARQ_CALL_RETRY_SLOTS_DEFAULT

#define ARQ_CALL_RETRY_SLOTS_DEFAULT   4 /* CALL retries before giving up */

ARQ_CALLINT_DEFAULT_S

#define ARQ_CALLINT_DEFAULT_S   0.0f /* 0 = use table default */

ARQ_CALLINT_MIN_S

#define ARQ_CALLINT_MIN_S   4.0f

ARQ_CHANNEL_DEFER_MAX

#define ARQ_CHANNEL_DEFER_MAX   20 /* ~10 s, then key regardless */

ARQ_CHANNEL_DEFER_MS

#define ARQ_CHANNEL_DEFER_MS   500

ARQ_CHANNEL_GUARD_MS

#define ARQ_CHANNEL_GUARD_MS

Value:

                                                700   /* IRS response guard after frame decode.
                                                * OFDM decode fires ~200ms before sender
                                                * PTT-OFF, so effective gap at sender is
                                                * (guard - 200ms) ~= 500ms.  Radio needs
                                                * ~340ms for TX->RX switch -> 160ms margin
                                                * for preamble detection.  At 500ms the
                                                * effective gap was ~300ms, causing ~50%
                                                * ACK loss on DATAC1 (< 340ms switch).  */

ARQ_CHANNEL_SYNC_HOLD_MS

#define ARQ_CHANNEL_SYNC_HOLD_MS   250

ARQ_CONNECT_ACCEPT_FLAG

#define ARQ_CONNECT_ACCEPT_FLAG   0x80

ARQ_CONNECT_DST_CRC_SIZE

#define ARQ_CONNECT_DST_CRC_SIZE   2 /* CRC16-CCITT of DST at bytes [2..3], little-endian */

ARQ_CONNECT_EXT_BW_MASK

#define ARQ_CONNECT_EXT_BW_MASK   0x03

ARQ_CONNECT_EXT_CAROUSEL

#define ARQ_CONNECT_EXT_CAROUSEL   0x10

ARQ_CONNECT_EXT_VERSION_MASK

#define ARQ_CONNECT_EXT_VERSION_MASK   0x0C

ARQ_CONNECT_EXT_VERSION_SHIFT

#define ARQ_CONNECT_EXT_VERSION_SHIFT   2

ARQ_CONNECT_MAX_ENCODED

#define ARQ_CONNECT_MAX_ENCODED   (ARQ_CONTROL_FRAME_SIZE - ARQ_CONNECT_META_SIZE)

ARQ_CONNECT_META_SIZE

#define ARQ_CONNECT_META_SIZE   2 /* framer byte + connect_meta byte */

ARQ_CONNECT_PAYLOAD_IDX

#define ARQ_CONNECT_PAYLOAD_IDX   2

ARQ_CONNECT_SESSION_IDX

#define ARQ_CONNECT_SESSION_IDX   1

ARQ_CONNECT_SESSION_MASK

#define ARQ_CONNECT_SESSION_MASK   0x7F

ARQ_CONNECT_SRC_MAX_ENCODED

#define ARQ_CONNECT_SRC_MAX_ENCODED   (ARQ_CONNECT_MAX_ENCODED - ARQ_CONNECT_DST_CRC_SIZE) /* 10 */

ARQ_CONNECT_VERSION

#define ARQ_CONNECT_VERSION   1

ARQ_CONTROL_FRAME_SIZE

#define ARQ_CONTROL_FRAME_SIZE   14

ARQ_CONTROL_MODE

#define ARQ_CONTROL_MODE   FREEDV_MODE_DATAC16

ARQ_CQ_PAYLOAD_IDX

#define ARQ_CQ_PAYLOAD_IDX   1

ARQ_CQ_SRC_MAX_ENCODED

#define ARQ_CQ_SRC_MAX_ENCODED   (ARQ_CONTROL_FRAME_SIZE - ARQ_CQ_PAYLOAD_IDX) /* 13 */

ARQ_DISCONNECT_DRAIN_TIMEOUT_S

#define ARQ_DISCONNECT_DRAIN_TIMEOUT_S   atomic_load(&arq_disconnect_drain_timeout_s)

ARQ_DISCONNECT_DRAIN_TIMEOUT_S_DEFAULT

#define ARQ_DISCONNECT_DRAIN_TIMEOUT_S_DEFAULT   45

ARQ_DISCONNECT_RETRY_SLOTS

#define ARQ_DISCONNECT_RETRY_SLOTS   atomic_load(&arq_disconnect_retry_slots)

ARQ_DISCONNECT_RETRY_SLOTS_DEFAULT

#define ARQ_DISCONNECT_RETRY_SLOTS_DEFAULT   2 /* DISCONNECT frame retries */

ARQ_FRAME_HDR_SIZE

#define ARQ_FRAME_HDR_SIZE   8 /* bytes 0-7 inclusive */

ARQ_HDR_ACK_IDX

#define ARQ_HDR_ACK_IDX   5

ARQ_HDR_DELAY_IDX

#define ARQ_HDR_DELAY_IDX   7

ARQ_HDR_FLAGS_IDX

#define ARQ_HDR_FLAGS_IDX   2

ARQ_HDR_SEQ_IDX

#define ARQ_HDR_SEQ_IDX   4

ARQ_HDR_SESSION_IDX

#define ARQ_HDR_SESSION_IDX   3

ARQ_HDR_SNR_IDX

#define ARQ_HDR_SNR_IDX   6

ARQ_HDR_SUBTYPE_IDX

#define ARQ_HDR_SUBTYPE_IDX   1

ARQ_ISS_POST_ACK_GUARD_MS

#define ARQ_ISS_POST_ACK_GUARD_MS

Value:

                                                900   /* ISS guard before resuming DATA TX
                                                * after receiving an ACK from the IRS.
                                                * Larger than ARQ_CHANNEL_GUARD_MS:
                                                * ack_rx fires ~168ms before IRS PTT-OFF,
                                                * so the effective gap at IRS is only
                                                * (guard + 100ms head) - 168ms.
                                                * At 500ms: gap=432ms, too tight for
                                                * DATAC1 re-sync after IRS ACK TX.
                                                * At 900ms: gap=832ms -- 492ms of clear
                                                * air before the DATAC1 preamble. */

ARQ_LISTEN_OFF_GRACE_MS

#define ARQ_LISTEN_OFF_GRACE_MS   2000

ARQ_REPLY_WINDOW_MARGIN_MS

#define ARQ_REPLY_WINDOW_MARGIN_MS   1000

ARQ_RETRY_STAGGER_MS_DEFAULT

#define ARQ_RETRY_STAGGER_MS_DEFAULT   2000

ARQ_RETRY_STAGGER_MS_MAX

#define ARQ_RETRY_STAGGER_MS_MAX   5000

ARQ_SNR_HYST_DB

#define ARQ_SNR_HYST_DB   5.0f

ARQ_SNR_MIN_DATAC15_DB

#define ARQ_SNR_MIN_DATAC15_DB

Value:

                                             -7.0f  /* its cliff (sim, bench): below
                                             * it the carousel's MFSK rung wins */

ARQ_SNR_MIN_DATAC17_DB

#define ARQ_SNR_MIN_DATAC17_DB

Value:

                                             7.0f  /* bench (docs/MODES.md): goodput
                                             * crossover vs DATAC1 ~ +6 dB MPP;
                                             * 89/100 delivery at +8          */

ARQ_SNR_MIN_DATAC1_DB

#define ARQ_SNR_MIN_DATAC1_DB   3.0f

ARQ_SNR_MIN_DATAC3_DB

#define ARQ_SNR_MIN_DATAC3_DB   -1.0f

ARQ_SNR_MIN_DATAC4_DB

#define ARQ_SNR_MIN_DATAC4_DB

Value:

                                             -6.0f  /* bench (docs/MODES.md):
                                             * DATAC15/DATAC4 goodput crossover
                                             * ~-7.5 dB MPP / -8.5 dB AWGN     */

ARQ_SNR_MIN_QAM16C2_DB

#define ARQ_SNR_MIN_QAM16C2_DB

Value:

                                             13.0f  /* bench: goodput crossover vs
                                             * DATAC17 ~ +11 dB MPP, 84/100 at
                                             * +13.7; upstream's published
                                             * operating point is +15        */

Enumeration Type Documentation

arq_subtype_t

enum arq_subtype_t

Enumerator
ARQ_SUBTYPE_DISCONNECT

Function Documentation

arq_protocol_build_accept()

int arq_protocol_build_accept	(	uint8_t *	buf,
		size_t	buf_len,
		uint8_t	session_id,
		const char *	called,
		const char *	caller,
		int	bw_hz,
		int	start_level,
		uint16_t	nonce
	)

Build an ACCEPT.

called: the callsign the CALL was addressed to (the callee's primary or a secondary); start_level 0..6, or ARQ_ACCEPT_LEVEL_CTL_DEAF.

Returns

ARQ_CONTROL_FRAME_SIZE (14), or -1.

arq_protocol_build_call()

int arq_protocol_build_call	(	uint8_t *	buf,
		size_t	buf_len,
		uint8_t	session_id,
		const char *	caller,
		const char *	called,
		int	bw_hz
	)

Build a CALL.

Returns

ARQ_CONTROL_FRAME_SIZE (14), or -1.

arq_protocol_build_cq()

int arq_protocol_build_cq	(	uint8_t *	buf,
		size_t	buf_len,
		const char *	src,
		int	bw_hz
	)

Build a compact DATAC16 CQ frame carrying source callsign and BW token.

arq_protocol_build_disconnect()

int arq_protocol_build_disconnect	(	uint8_t *	buf,
		size_t	buf_len,
		uint8_t	session_id,
		uint8_t	snr_raw
	)

DISCONNECT frame (PACKET_TYPE_ARQ_CONTROL).

arq_protocol_bw_hz_from_token()

int arq_protocol_bw_hz_from_token

(

uint8_t

bw_token

)

Map an on-air BW token back to Hz.

Returns

500/2300/2750 on success, or 0 if the token is invalid.

arq_protocol_bw_token_from_hz()

uint8_t arq_protocol_bw_token_from_hz

(

int

bw_hz

)

Map a configured bandwidth in Hz to an on-air BW token.

Returns

ARQ_BW_TOKEN_* value, or ARQ_BW_TOKEN_NONE if unsupported.

arq_protocol_call_interval_for_mode_s()

float arq_protocol_call_interval_for_mode_s

(

int

mode

)

arq_protocol_call_interval_s()

float arq_protocol_call_interval_s

(

void

)

Return the CALL/ACCEPT retry interval in seconds, applying any CALLINT override.

Falls back to the DATAC16 table default (8.0s).

arq_protocol_callsign_crc16()

uint16_t arq_protocol_callsign_crc16

(

const char *

callsign

)

Compute CRC16-CCITT of an uppercase-normalised callsign.

Used to encode/validate the DST field in CALL/ACCEPT frames.

arq_protocol_connect_dst_matches()

bool arq_protocol_connect_dst_matches	(	const uint8_t *	buf,
		const char *	callsign
	)

Is a CALL or ACCEPT addressed to callsign (bytes 2-3, all 16 bits)?

arq_protocol_connect_version_ok()

bool arq_protocol_connect_version_ok	(	const uint8_t *	buf,
		size_t	buf_len
	)

Is buf a CALL or ACCEPT of this protocol version?

arq_protocol_decode_hdr()

int arq_protocol_decode_hdr	(	const uint8_t *	buf,
		size_t	buf_len,
		arq_frame_hdr_t *	hdr
	)

Decode the ARQ header from the first bytes of buf.

Returns

0 on success, -1 if buf too short.

arq_protocol_decode_snr()

float arq_protocol_decode_snr

(

uint8_t

snr_raw

)

Decode snr_raw wire byte back to float dB.

Returns

SNR in dB, or 0.0f if snr_raw == 0 (unknown).

arq_protocol_encode_hdr()

int arq_protocol_encode_hdr	(	uint8_t *	buf,
		size_t	buf_len,
		const arq_frame_hdr_t *	hdr
	)

Encode a parsed header into the first ARQ_FRAME_HDR_SIZE bytes of buf.

Returns

0 on success, -1 if buf_len < ARQ_FRAME_HDR_SIZE.

arq_protocol_encode_snr()

uint8_t arq_protocol_encode_snr

(

float

snr_db

)

Encode a floating-point SNR (dB) into the snr_raw wire byte.

Returns

Encoded byte (0 if snr_db is out of range or unknown).

arq_protocol_longest_burst_s()

float arq_protocol_longest_burst_s

(

void

)

Longest single-burst airtime across the whole mode table, in seconds.

The RX side must be able to hold a burst of ANY mode the peer might send, not just the one currently selected — the peer can change rung between our bursts, and the first frame of the new rung arrives before we know about it. Buffers sized from the active mode are therefore always one step behind.

arq_protocol_mode_timing()

const arq_mode_timing_t * arq_protocol_mode_timing

(

int

freedv_mode

)

Look up mode timing entry for a FreeDV mode.

Returns

Pointer to timing entry, or NULL if mode is unknown.

arq_protocol_parse_accept()

int arq_protocol_parse_accept	(	const uint8_t *	buf,
		size_t	buf_len,
		arq_accept_t *	out
	)

Parse an ACCEPT.

Returns

0, or -1 (wrong version, bad bandwidth token, a reserved bit set, a start rung off the ladder).

arq_protocol_parse_call()

int arq_protocol_parse_call	(	const uint8_t *	buf,
		size_t	buf_len,
		uint8_t *	session_id_out,
		char *	caller_out,
		int *	bw_hz_out
	)

Parse a CALL: session id, the caller's callsign, the bandwidth.

Returns

0, or -1 (wrong version, bad bandwidth token, undecodable call).

arq_protocol_parse_cq()

int arq_protocol_parse_cq	(	const uint8_t *	buf,
		size_t	buf_len,
		char *	src_out,
		int *	bw_hz_out
	)

Parse a compact DATAC16 CQ frame.

arq_protocol_retry_deadline_ms()

uint64_t arq_protocol_retry_deadline_ms	(	float	seconds,
		int	rank
	)

arq_protocol_retry_rank()

int arq_protocol_retry_rank	(	const char *	local_call,
		const char *	remote_call
	)

Variable Documentation

arq_accept_retry_slots

_Atomic int arq_accept_retry_slots

extern

arq_call_retry_slots

_Atomic int arq_call_retry_slots

extern

arq_callint_override_s

_Atomic float arq_callint_override_s

extern

arq_disconnect_drain_timeout_s

_Atomic int arq_disconnect_drain_timeout_s

extern

arq_disconnect_retry_slots

_Atomic int arq_disconnect_retry_slots

extern

arq_mode_table

const arq_mode_timing_t arq_mode_table[]

extern

arq_mode_table_count

const int arq_mode_table_count

extern

arq_retry_stagger_ms

_Atomic int arq_retry_stagger_ms

extern