Registrar

The Centrex Proxy Server® includes integrated registrar capabilities. Registrar capabilities allow the Centrex Proxy Server® to maintain a list of "registered" users in your VOIP domain and to route calls to destinations within your domain. You can think of the registrar capabilities as maintaining a list of all users that are currently "logged into" your VOIP domain.

For most small to medium deployments, you can use all of the default settings. There are no additional database or 3rd party software requirements. For larger deployments where more than one Centrex Proxy Server® will be used, the Centrex Proxy Server® supports the use of a shared database that can be hosted on any machine in your network. To use the shared database capability, you must have installed the appropriate ODBC database drivers on the host that is running the Centrex Proxy Server® software. You also may need other 3rd party database support depending on what database technology you chose (i.e MySQL, Microsoft Access, SQL, etc).


The following dialog is used to specify registrar settings for the Centrex Proxy Server®:
 

The registrar function of the Centrex Proxy Server® requires a name. You can specify any valid SIP user name or unused phone extension in this field.



Registrar is case sensitive:

This setting allows you to specify if your registration database is case sensitive. If you assign phone numbers to your VOIP domain that consist of only numbers (extension numbers), you do not have to be concerned with this setting. If however you allow users to have valid SIP user names that contains characters, then you can specify case enforcement using this setting.



Default Registration Time (Seconds):

This values allows you to configure the default registration interval that will be applied if a SIP user agent registers and does not explicitly define the registration duration using a SIP "Expires" header or a SIP "expires" parameter in SIP "Contact" headers.



Use memory cache registrar database with recovery file:

For most installations, you will want to select this option. When you do, the registrar database information is maintained in memory. For crash recovery purposes, the registrar database information is also written to a recovery file image. This registrar scheme is very fast and is suitable for most uses.



Update recovery file every 'X' registrations:

This setting controls how often the registry database recovery file is updated. You might want to increase this value to obtain improved registration performance.



Update recovery file every 'X' seconds:

This setting also controls how often the registry database recovery file is updated. The registry database information will periodically be written to the recovery file image at this interval (if it has changed).

 

Use database interface:

If you deploy more than one Centrex Proxy Server® and they are being used to load share the same domain or load sharing multiple related domains, then you will want to select this setting. Using this setting allows the registration database to be external to the Centrex Proxy Server® application. What this means is that two or more Centrex Proxy Servers can share the same registration database for the same domain. You can also share a single registration database between multiple related domains.

The Centrex Proxy Server® is shipped with an empty Microsoft Access registrar database and an empty MySQL database that you can use as a starting point. Note that you can use any back end database support you desire. The only requirement is that proper ODBC drivers be installed on each host machine that executes the Centrex Proxy Server® software.

Example: Creating a large single phone system using multiple proxies
Lets assume you would like to deploy 15 Centrex Proxy Servers all to different office locations. We assume that each deployed Centrex Proxy Server® will be deployed such that it can be resolved via DNS (static or dynamic). The 15 separate Centrex Proxy Servers are all configured to access the same common registrar database located somewhere in the global network. Because the deployed proxies all manage their own DNS resolved domains but share the same registrar database, all 15 deployed proxies are considered to be "related". Because the domains are all sharing the same "registration data set" and because of the special capabilities of the Centrex Proxy Server®, users can call into another domain seamlessly without having to know anything about the destination domain name. Using the capability, very large and scalable deployments can be achieved



Database Interface Driver:

Allows you to specify and configure a LanScape registrar database driver that can be used to access your external registration database. This additional capability is supplied by LanScape as a dynamic Link Library (not included in the Personal version of the proxy). You must use this setting to specify the location of this DLL driver. The name of the driver DLL is RegistrarDatabaseDriver.dll.



Configure Database Driver:

Once the external database driver DLL is located, you can press this button to configure your external database settings. When you press this button, the following dialog will be displayed:








Note: The LanScape Centrex Proxy Server® ships with an empty Microsoft Access and MySQL registrar database images.


If you are planning to use an external Microsoft Access registrar database image, you can use this dialog to select the database file image (*,mdb). Optionally supply a valid username and password if required. Once you have selected your database image, press the "Test Connection" button to verify that you can access the database. Press the OK button when you are finished.

If you are planning to use an external MySQL database, you can use this dialog to specify the ODBC driver settings that are required to access the database. In this case, you will want to enable the "Use custom connect string" in the dialog shown above. When you enable this setting, the edit control will be enabled and you can enter your ODBC connect string.

Next we will present a few ODBC configuration examples that will help to clarify what is required.


Example 1 - Access database on the local machine:
Driver={Microsoft Access Driver (*.mdb)};

Dbq=D:\MyRegistrarDatabase\RegistrarDatabase.mdb;

Uid=;

Pwd=;

 

Example 2 - Access database on remote machine. Requires a share to be created:

Driver={Microsoft Access Driver (*.mdb)};

Dbq=\\DatabaseServer\D\MyRegistrarDatabase\RegistrarDatabase.mdb;

Uid=;

Pwd=;

 

Example 3 - Access database on remote machine, using IP address. Requires a share to be created:

Driver={Microsoft Access Driver (*.mdb)};

Dbq=\\192.168.1.80\D\MyRegistrarDatabase\RegistrarDatabase.mdb;

Uid=;

Pwd=;


Example 4 - MySQL database on local machine:

Driver={MySQL ODBC 3.51 Driver};

Server=localhost;

Database=registrardatabase;

User=root;

Password=rootpassword;

Option=4;


Example 5 - MySQL database on a remote machine:

Driver={MySQL ODBC 3.51 Driver};

Server=DatabaseServer;

Database=registrardatabase;

User=root;

Password=rootpassword;

Option=4;

Once you specify your ODBC connect string in the dialog above, you can verify that you can connect to the database by pressing the "Test Connection" button.

Monitor registration database for expired entries:

When this setting is enabled, it allows the Centrex Proxy Server® to remove all expired registration entries from the user database. This capability is enabled as a precautionary measure against SIP clients who do not un-register with the Centrex Proxy Server®. This setting helps to keep database and memory requirements low.



Enable Registrar (Presence) events:

The Centrex Proxy Server® has the ability to send SIP NOTIFY events to user who wish to receive them. NOTIFY events are sent to a user when someone new registers with the VOIP domain or if a user leaves (un-registers) from the VOIP domain. The NOTIFY events that are sent allows intelligent SIP clients to maintain a list of who is available for calls. This type of functionality is termed "presence" information. All LanScape soft phones support this capability.

In general, when a soft phone starts up, it firsts registers with the Centrex Proxy Server®. Immediately after, it can then SUBSCRIBE to Centrex Proxy Server® registration events. After successfully subscribing to registrar events, the Centrex Proxy Server® will send NOTIFY sip events to the SIP client. The following SIP protocol log will help to clarify:



SIP transactions when a user agent subscribes to registrar events:

The SIP user agent is subscribing to the "user available" event. This
event is used to inform UAs when someone new enters the domain.

>>>> TxTxTxTxTxTxTxTxTxTxTxTxTxTxTxTxTxTxTx (63 Ms, To: 192.168.1.2:7000) >>>>

SUBSCRIBE sip:Registrar@lanscapecorp.com:7000 SIP/2.0

Via: SIP/2.0/UDP 192.168.1.2:10000

From: <sip:1244@lanscapecorp.com:7000>;tag=17da23c

To: <sip:Registrar@lanscapecorp.com:7000>

Call-Id: ad2b9eed-c075-4d02-9707-55c1853a9114-00000498@192.168.1.2

CSeq: 24992323 SUBSCRIBE

Expires: 3600

Max-Forwards: 70

Contact: <sip:1244@lanscapecorp.com:7000>

User-Agent: LanScape VOIP Media Engine/5.11.0205 (www.LanScapeCorp.com)

Event: user-available

Content-Length: 0
 

<<<< RxRxRxRxRxRxRxRxRxRxRxRxRxRxRxRxRxRx (0 Ms, From: 192.168.1.2:7000) <<<<

SIP/2.0 200 OK

Via: SIP/2.0/UDP 192.168.1.2:10000;received=192.168.1.2:10000

From: <sip:1244@lanscapecorp.com:7000>;tag=17da23c

To: <sip:Registrar@lanscapecorp.com:7000>

Call-ID: ad2b9eed-c075-4d02-9707-55c1853a9114-00000498@192.168.1.2

CSeq: 24992323 SUBSCRIBE

User-Agent: LanScape Centrex Proxy/3.40 (www.LanScapeCorp.com)

Content-Length: 0



The SIP user agent is now subscribing to the "user not available" event. This
event is used to inform UAs when someone leaves the domain.

>>>> TxTxTxTxTxTxTxTxTxTxTxTxTxTxTxTxTxTxTx (15 Ms, To: 192.168.1.2:7000) >>>>

SUBSCRIBE sip:Registrar@lanscapecorp.com:7000 SIP/2.0

Via: SIP/2.0/UDP 192.168.1.2:10000

From: <sip:1244@lanscapecorp.com:7000>;tag=17da24b

To: <sip:Registrar@lanscapecorp.com:7000>

Call-Id: 2c705f39-0782-4d7c-94e7-ea2809d07c54-00000498@192.168.1.2

CSeq: 24992338 SUBSCRIBE

Expires: 3600

Max-Forwards: 70

Contact: <sip:1244@lanscapecorp.com:7000>

User-Agent: LanScape VOIP Media Engine/5.11.0205 (www.LanScapeCorp.com)

Event: user-unavailable

Content-Length: 0

<<<< RxRxRxRxRxRxRxRxRxRxRxRxRxRxRxRxRxRx (15 Ms, From: 192.168.1.2:7000) <<<<

SIP/2.0 200 OK

Via: SIP/2.0/UDP 192.168.1.2:10000;received=192.168.1.2:10000

From: <sip:1244@lanscapecorp.com:7000>;tag=17da24b

To: <sip:Registrar@lanscapecorp.com:7000>

Call-ID: 2c705f39-0782-4d7c-94e7-ea2809d07c54-00000498@192.168.1.2

CSeq: 24992338 SUBSCRIBE

User-Agent: LanScape Centrex Proxy/3.40 (www.LanScapeCorp.com)

Content-Length: 0

Unsubscribing

The Centrex Proxy Server® starts to send "user-available" events to inform

the user agent about new users. the "param" value of the event header

contains a '|' delimited list of information. The first 2 fields are

for a single user. Field 1 specifies the SIP user agent name and field 2

is a description. Multiple NOTIFY SIP messages can be sent to a user agent

if there are many registered users.
 

<<<< RxRxRxRxRxRxRxRxRxRxRxRxRxRxRxRxRxRx (47 Ms, From: 192.168.1.2:7000) <<<<

NOTIFY sip:1244@192.168.1.2:10000 SIP/2.0

Via: SIP/2.0/UDP 192.168.1.2:7000;branch=z9hG4bKf43df9245731c4422d1789454ac3a4912

From: <sip:Registrar@192.168.1.2:7000>;tag=17d5a42

To: <sip:1244@192.168.1.2:10000>

Call-ID: 0a11d131-45c4-4cbd-89dc-d7f87afd622c@192.168.1.2

CSeq: 25010748 NOTIFY

Contact: <sip:Registrar@192.168.1.2:7000>

Event: user-available;param=voicemail|The company voicemail server|1234|Engineering Lab|1235|Ted McGraw|1236|Julie Marx|1237|Sales Department|1238|Tom Anderson|1239|Jack Crenshaw|1244|Temporary Visitor

Max-Forwards: 70

User-Agent: LanScape Centrex Proxy/3.40 (www.LanScapeCorp.com)

Content-Length: 0

>>>> TxTxTxTxTxTxTxTxTxTxTxTxTxTxTxTxTxTxTx (0 Ms, To: 192.168.1.2:7000) >>>>

SIP/2.0 200 OK

Via: SIP/2.0/UDP 192.168.1.2:7000;branch=z9hG4bKf43df9245731c4422d1789454ac3a4912

From: <sip:Registrar@192.168.1.2:7000>;tag=17d5a42

To: <sip:1244@192.168.1.2:10000>

Call-Id: 0a11d131-45c4-4cbd-89dc-d7f87afd622c@192.168.1.2

CSeq: 25010748 NOTIFY

User-Agent: LanScape VOIP Media Engine/5.11.0205 (www.LanScapeCorp.com)

Content-Length: 0


.

.

The SIP user agent may be logged into the VOIP domain for hours and hours...

.

.

.


The SIP user agent is now going to un-subscribe from the registrar events.
Notice the zero specified Expires time for both requests.

>>>> TxTxTxTxTxTxTxTxTxTxTxTxTxTxTxTxTxTxTx (8407 Ms, To: 192.168.1.2:7000) >>>>

SUBSCRIBE sip:Registrar@lanscapecorp.com:7000 SIP/2.0

Via: SIP/2.0/UDP 192.168.1.2:10000

From: <sip:1244@lanscapecorp.com:7000>;tag=17de283

To: <sip:Registrar@lanscapecorp.com:7000>

Call-Id: 5ed36358-def4-495e-969b-e4e878782025-00000498@192.168.1.2

CSeq: 25007038 SUBSCRIBE

Expires: 0

Max-Forwards: 70

Contact: <sip:1244@lanscapecorp.com:7000>

User-Agent: LanScape VOIP Media Engine/5.11.0205 (www.LanScapeCorp.com)

Event: user-available

Content-Length: 0

<<<< RxRxRxRxRxRxRxRxRxRxRxRxRxRxRxRxRxRx (8407 Ms, From: 192.168.1.2:7000) <<<<

SIP/2.0 200 OK

Via: SIP/2.0/UDP 192.168.1.2:10000;received=192.168.1.2:10000

From: <sip:1244@lanscapecorp.com:7000>;tag=17de283

To: <sip:Registrar@lanscapecorp.com:7000>

Call-ID: 5ed36358-def4-495e-969b-e4e878782025-00000498@192.168.1.2

CSeq: 25007038 SUBSCRIBE

User-Agent: LanScape Centrex Proxy/3.40 (www.LanScapeCorp.com)

Content-Length: 0

>>>> TxTxTxTxTxTxTxTxTxTxTxTxTxTxTxTxTxTxTx (31 Ms, To: 192.168.1.2:7000) >>>>

SUBSCRIBE sip:Registrar@lanscapecorp.com:7000 SIP/2.0

Via: SIP/2.0/UDP 192.168.1.2:10000

From: <sip:1244@lanscapecorp.com:7000>;tag=17de2a2

To: <sip:Registrar@lanscapecorp.com:7000>

Call-Id: 867704cb-2579-40fd-8828-833dfdb5c612-00000498@192.168.1.2

CSeq: 25007069 SUBSCRIBE

Expires: 0

Max-Forwards: 70

Contact: <sip:1244@lanscapecorp.com:7000>

User-Agent: LanScape VOIP Media Engine/5.11.0205 (www.LanScapeCorp.com)

Event: user-unavailable

Content-Length: 0

<<<< RxRxRxRxRxRxRxRxRxRxRxRxRxRxRxRxRxRx (31 Ms, From: 192.168.1.2:7000) <<<<

SIP/2.0 200 OK

Via: SIP/2.0/UDP 192.168.1.2:10000;received=192.168.1.2:10000

From: <sip:1244@lanscapecorp.com:7000>;tag=17de2a2

To: <sip:Registrar@lanscapecorp.com:7000>

Call-ID: 867704cb-2579-40fd-8828-833dfdb5c612-00000498@192.168.1.2

CSeq: 25007069 SUBSCRIBE

User-Agent: LanScape Centrex Proxy/3.40 (www.LanScapeCorp.com)

Content-Length: 0

Registrar Event Names:

You can change the names of the "user-available" and "user-unavailable" notification events described above. If the default names are not suitable, change them to whatever you require.