kamailio.cfg: explicitely set the tcp/tls connections upper limits

- notes about tcp_children and relation with children parameter

(cherry picked from commit 409cb202057c89e87d910a1877ce719c6335ebdb)

etc/kamailio.cfg

@@ -158,12 +158,16 @@ memlog=5
 log_facility=LOG_LOCAL0
 log_prefix="{$mt $hdr(CSeq) $ci} "
 
-/* number of SIP routing processes */
+/* number of SIP routing processes for each UDP socket
+ * - value inherited by tcp_children and sctp_children when not set explicitely */
 children=8
 
 /* uncomment the next line to disable TCP (default on) */
 # disable_tcp=yes
 
+/* number of SIP routing processes for all TCP/TLS sockets */
+# tcp_children=8
+
 /* uncomment the next line to disable the auto discovery of local aliases
  * based on reverse DNS on IPs (default on) */
 # auto_aliases=no
@@ -175,14 +179,20 @@ children=8
  * bind on a specific interface/port/proto (default bind on all available) */
 # listen=udp:10.0.0.10:5060
 
-#!ifdef WITH_TLS
-enable_tls=yes
-#!endif
-
 /* life time of TCP connection when there is no traffic
  * - a bit higher than registration expires to cope with UA behind NAT */
 tcp_connection_lifetime=3605
 
+/* upper limit for TCP connections (it includes the TLS connections) */
+tcp_max_connections=2048
+
+#!ifdef WITH_TLS
+enable_tls=yes
+
+/* upper limit for TLS connections */
+tls_max_connections=2048
+#!endif
+
 ####### Custom Parameters #########
 
 /* These parameters can be modified runtime via RPC interface