Dialog and Profile replication in a cluster in EF SIP Proxy

In a clustered environment within EF SIP proxy, dialog and profile replication play critical roles in ensuring seamless communication and maintaining consistency across nodes. Dialog replication refers to the process of synchronizing ongoing dialogs between nodes, ensuring that all nodes within the cluster have real-time access to the same dialog state. Profile replication involves replicating call profiles across nodes. Profiles replication allows to know the number of all calls within the cluster. Also, we can limit the number of concurrent calls for one profile.

Requirements

To share the dialogs and profiles with all nodes of the EF SIP Proxy cluster, we require a minimum of two EF SIP Proxy servers with clustering configured. Additionally, it is essential to ensure that the machines are running PHP 7.4. The control panel may experience issues if other PHP versions are used.

Step 1: Configuring clustering

To configure clustering follow this document.

Step 2: Modifying opensips.cfg

Open opensips.cfg file in server 1 to change the dialog location module configuration, and add lines for dialog and profiles.

CODE

#### Dialog Module
loadmodule "dialog.so"
modparam("dialog", "profiles_with_value", "caller ; domain") #to track dialog profiles based on the values of caller and domain
modparam("dialog", "db_mode", 2) #enabling dialog state storage in the DB
modparam("dialog", "dialog_replication_cluster", CLUSTER_ID) #enable dialog replication across the cluster with CLUSTER ID
modparam("dialog", "db_url",
        "mysql://opensips:opensipsrw@localhost/opensips")
modparam("dialog", "profile_replication_cluster", 1) # #enable profile replication across the cluster with CLUSTER ID
modparam("dialog", "profiles_no_value", "CCcalls/b") # specify profile for dialogs with no profile value

Replace CLUSTER_ID with the real ID of the cluster set in Step 1

Add the following lines in if(is_method("INVITE")) {} condition of route{}

CODE

 if(is_method("INVITE")) {
                create_dialog("B");  # Create a new dialog of type "B"
                $DLG_timeout=7200;  # Set the dialog timeout to 7200 seconds
                set_dlg_profile("CCcalls/b");  # Set the dialog profile to "CCcalls/b"
                set_dlg_sharing_tag("vip");  # Set a sharing tag for the dialog
                set_dlg_profile("caller","$fU@$fd");  # Set the dialog profile for the "caller" attribute 
                set_dlg_profile("domain","$fd");  # Set the dialog profile for the "domain" attribute
                get_profile_size("caller","$fU@$fd",$var(ccaller));  # Get the size of the "caller" profile
                get_profile_size("domain","$fd",$var(cdomain));  # Get the size of the "domain" profile
                xlog("L_INFO", "Number of calls from user $fU@$fd is $var(ccaller)\n");  # Log the number of calls for user
                xlog("L_INFO", "Number of calls from domain $fd is $var(cdomain)\n");  # Log the number of calls for domain
        }

Save this file and restart opensips.
CODE
```
sudo systemctl restart opensips.service
```
Repeat the same process for the other node server.

Testing

Make some calls from any of the node and run the following commands to
List all the ongoing dialogs in the cluster
CODE
```
opensips-cli -x mi dlg_list
```

List all the dialogs of CCcalls/b profile

CODE

opensips-cli -x mi profile_list_dlgs CCcalls/b

List the contexts of all dialogs
CODE
```
opensips-cli -x mi dlg_list_ctx
```
Get the number of ongoing calls of CCcalls/b profile
CODE
```
opensips-cli -x mi profile_get_size CCcalls/b
```