Alright, let's break down how to get your SIP infrastructure fully functional with the setup you've laid out. I’ll walk through each critical component step by step, tailored to your Debian 8 environment.

Network reachability is the foundation of your SIP stack—let’s lock this down first:

• OpenSIPS Server: Since its eth1 is on 192.168.1.4 with a public gateway (xxx.xx.xx.xy), add a static route to ensure it can reach the internal 192.168.1.0/24 subnet:

  ip route add 192.168.1.0/24 dev eth1
  

  To make this persistent across reboots, edit /etc/network/interfaces and add to the eth1 config block:

  up ip route add 192.168.1.0/24 dev eth1
  

• Other Devices: Confirm FreeSWITCH (192.168.1.2) and MySQL (192.168.1.3) can ping the SIP relay (192.168.1.5) and OpenSIPS’s eth1. Verify their gateway is set to 192.168.1.5 with ip route show.
• SIP Relay: Ensure the supplier’s relay can ping OpenSIPS’s 192.168.1.4 and FreeSWITCH’s 192.168.1.2.

Configure OpenSIPS to route calls to/from your supplier’s SIP relay by editing /etc/opensips/opensips.cfg:

1. Load required modules and define the trunk:

   # Load dispatcher module for trunk routing
   loadmodule "dispatcher.so"
   modparam("dispatcher", "list_file", "/etc/opensips/dispatcher.list")
   
   # Define trunk destination in dispatcher.list
   # Format: group_id, SIP URI, flags, priority
   # Add this line to /etc/opensips/dispatcher.list
   1 sip:192.168.1.5:5060 0 1
   

2. Add routing logic for trunk traffic:
   Insert this into your main route block:

   # Handle incoming calls from the SIP trunk
   if(src_ip == "192.168.1.5") {
       route(forward_to_freeswitch);
       exit;
   }
   
   # Handle outbound calls to external numbers via the trunk
   if($rU =~ /^\+?[0-9]{10,15}$/) { # Match E.164 number format
       ds_select_dst(1, 0); # Pick a trunk from dispatcher group 1
       t_relay();
       exit;
   }
   

3. Restart OpenSIPS:

   service opensips restart
   

Set up call forwarding between OpenSIPS and FreeSWITCH, and ensure FreeSWITCH accepts traffic from OpenSIPS:

1. Add FreeSWITCH routing in OpenSIPS:
   Create a dedicated route to forward calls to FreeSWITCH:

   route(forward_to_freeswitch) {
       $du = "sip:192.168.1.2:5060"; # FreeSWITCH's SIP address
       t_relay();
       exit;
   }
   

2. Configure FreeSWITCH to allow OpenSIPS traffic:
   Edit /etc/freeswitch/sip_profiles/internal.xml and add OpenSIPS’s eth1 IP to allowed networks:

   <param name="allow-ip" value="192.168.1.4/24"/>
   

3. Restart FreeSWITCH:

   service freeswitch restart
   

Connect OpenSIPS to your MySQL server for user authentication, call detail records (CDRs), and more:

1. Install the OpenSIPS MySQL module:

   apt-get install opensips-mysql-module
   

2. Set up the MySQL database and user:
   Log into your MySQL server (192.168.1.3) and run these commands:

   CREATE DATABASE opensips;
   GRANT ALL PRIVILEGES ON opensips.* TO 'opensips'@'192.168.1.4' IDENTIFIED BY 'your_secure_password_here';
   FLUSH PRIVILEGES;
   

3. Import OpenSIPS’s default database schema:
   On the OpenSIPS server, run:

   opensipsdbctl create
   

   Select MySQL when prompted, then enter your database credentials (192.168.1.3, opensips, and your password).
4. Enable MySQL integration in OpenSIPS:
   Add this to opensips.cfg:

   loadmodule "db_mysql.so"
   modparam("db_mysql", "db_url", "mysql://opensips:your_secure_password_here@192.168.1.3/opensips")
   
   # Optional: Enable user authentication
   loadmodule "auth.so"
   loadmodule "auth_db.so"
   modparam("auth_db", "calculate_ha1", yes)
   modparam("auth_db", "password_column", "password")
   

Verify each part of your stack works as expected:

• Outbound Call: Use a softphone registered to OpenSIPS to dial an external number. Check if the call routes through the SIP relay and FreeSWITCH handles media.
• Inbound Call: Ask your supplier to send a test call to the SIP relay. Confirm it’s forwarded to FreeSWITCH and reaches your endpoint.
• Database Sync: Register a new user via your softphone, then check MySQL’s subscriber table to ensure the record is saved.

• Firewall Rules: Open SIP (UDP 5060) and media ports (UDP 10000-20000) on all servers with ufw allow 5060/udp and ufw allow 10000:20000/udp.
• Logs: Check OpenSIPS logs at /var/log/opensips/, FreeSWITCH logs at /var/log/freeswitch/, and MySQL logs at /var/log/mysql/ for errors.
• Status Checks: Use opensips-cli -x mi show dispatcher to verify trunk status, and sip show peers in the FreeSWITCH console to check connections.

内容的提问来源于stack exchange，提问作者Menpress Malatae