# Configuration Variables for tcp

## tcp.connect_timeout

used only in non-async mode, in seconds.

Range: -1 - 134217727.

Type: integer.

## tcp.send_timeout

in seconds.

Range: -1 - 2147483647.

Type: integer.

## tcp.connection_lifetime

connection lifetime (in seconds).

Range: -1 - 2147483647.

Type: integer.

## tcp.max_connections

maximum tcp connections number, soft limit.

Range: 0 - 2147483647.

Type: integer.

## tcp.max_tls_connections

maximum tls connections number, soft limit.

Range: 0 - 2147483647.

Type: integer.

## tcp.no_connect

if set only accept new connections, never actively open new ones.

Range: 0 - 1.

Type: integer.

## tcp.fd_cache

file descriptor cache for tcp_send.

Range: 0 - 1.

Type: integer.

Read-only.

## tcp.async

async mode for writes and connects.

Range: 0 - 1.

Type: integer.

Read-only.

## tcp.connect_wait

parallel simultaneous connects to the same dst. (0) or one connect.

Range: 0 - 1.

Type: integer.

Read-only.

## tcp.conn_wq_max

maximum bytes queued for write per connection (depends on async).

Range: 0 - 1048576.

Type: integer.

## tcp.wq_max

maximum bytes queued for write allowed globally (depends on async).

Range: 0 - 1073741824.

Type: integer.

## tcp.defer_accept

0/1 on linux, seconds on freebsd (see docs).

Range: 0 - 3600.

Type: integer.

Read-only.

## tcp.delayed_ack

initial ack will be delayed and sent with the first data segment.

Range: 0 - 1.

Type: integer.

## tcp.syncnt

number of syn retransmissions before aborting a connect (0=not set).

Range: 0 - 1024.

Type: integer.

## tcp.linger2

lifetime of orphaned sockets in FIN_WAIT2 state in s (0=not set).

Range: 0 - 3600.

Type: integer.

## tcp.keepalive

enables/disables keepalives for tcp.

Range: 0 - 1.

Type: integer.

## tcp.keepidle

time before sending a keepalive if the connection is idle (linux).

Range: 0 - 86400.

Type: integer.

## tcp.keepintvl

time interval between keepalive probes on failure (linux).

Range: 0 - 86400.

Type: integer.

## tcp.keepcnt

number of failed keepalives before dropping the connection (linux).

Range: 0 - 1024.

Type: integer.

## tcp.crlf_ping

enable responding to CRLF SIP-level keepalives .

Range: 0 - 1.

Type: integer.

## tcp.accept_aliases

turn on/off tcp aliases (see tcp_accept_aliases) .

Range: 0 - 1.

Type: integer.

## tcp.alias_flags

flags used for adding new aliases (FORCE_ADD:1 , REPLACE:2) .

Range: 0 - 2.

Type: integer.

## tcp.new_conn_alias_flags

flags for the def. aliases for a new conn. (FORCE_ADD:1, REPLACE:2 .

Range: 0 - 2.

Type: integer.

## tcp.accept_no_cl

accept TCP messages without Content-Length .

Range: 0 - 1.

Type: integer.

## tcp.reuse_port

reuse TCP ports .

Range: 0 - 1.

Type: integer.

## tcp.rd_buf_size

internal read buffer size (should be > max. expected datagram).

Range: 512 - 16777216.

Type: integer.

## tcp.wq_blk_size

internal async write block size (debugging use only for now).

Range: 1 - 65535.

Type: integer.