deleted file mode 100644

@@ -1,259 +0,0 @@

-

-Least Cost Routing Module

-

-Juha Heinanen

-

-Edited by

-

-Juha Heinanen

-

-   Copyright � 2005 Juha Heinanen

-     _________________________________________________________

-

-   Table of Contents

-

-   1. User's Guide

-

-        1.1. Overview

-        1.2. Dependencies

-        1.3. Exported Parameters

-        1.4. Exported Functions

-        1.5. FIFO Commands

-        1.6. Known Limitations

-

-   2. TODO

-     _________________________________________________________

-

-Chapter 1. User's Guide

-

-1.1. Overview

-

-   Least cost routing (LCR) module implements two related capabilities:

-

-   (1) sequential forwarding of a request to one or more gateways

-       (functions load_gws and next_gw),

-

-   (2) sequential forwarding to contacts if they don't share the

-       the same qvalue (functions load_contacts and next_contacts).

-

-   Gateway selection is based on caller's RPID URI (if available in

-   caller's RPID AVP after authentication) or From URI and user part of

-   Request-URI (telephone number).  Gateway patterns matching RPID or

-   From URI and telephone number are ordered for forwarding purpose (1)

-   according to longest user part match, (2) according to priority, and

-   (3) randomly.

-

-   Each gateway belongs to a gateway group either alone or among other

-   gateways.  All gateways in a group share the same priority.

-

-   Gateway and routing information is kept in two tables:  gw and lcr.

-

-   When a gateway is selected, Request-URI is rewritten with information

-   from gw table: URI scheme, prefix, IP address, port, and transport

-   protocol.  Valid URI scheme values are NULL = sip, 1 = sip and 2 =

-   sips.  Prefix is appended in front of Request-URI user part.

-   Currently valid transport protocol values are NULL = none, 1 = udp, 2

-   = tcp, and 3 = tls.

-

-   Table lcr contains prefix of user part of Request-URI, From URI,

-   gateway group id, and priority.  From URI can contain special

-   characters % and _ matching any number of any characters and any one

-   character, respectively.  

-

-   In addition to gw and lcr tables there is third table gw_grp that is

-   used for administrative purposes only to associate names with gateway

-   group ids.

-   _________________________________________________________

-

-1.2. Dependencies

-

-   The module depends on the following modules (in the other

-   words the listed modules must be loaded before this module):

-

-     * tm module

-     * mysql module

-     _________________________________________________________

-

-1.3. Exported Parameters

-

-   LCR module exports the following database related parameters that

-   have usual purpose:

-

-     * db_url (default system default)

-     * gw_table (default "gw")

-     * gw_name_column (default "gw_name")

-     * ip_addr_column (default "ip_addr")

-     * port_column (default "port")

-     * uri_scheme_column (default "uri_scheme")

-     * transport_column (default "transport")

-     * grp_id_column (default "grp_id")

-     * lcr_table (default "lcr")

-     * prefix_column (default "prefix")

-     * from_uri_column (default "from_uri")

-     * priority_column (default "priority")

-

-   In addition there are parameters that can be used to override names

-   of the AVPs used by LCR module:

-

-     * gw_uri_avp	  (default "1400")

-     * contact_avp	  (default "1401")

-     * fr_inv_timer_avp	  (default "fr_inv_timer_avp")

-     * rpid_avp		  (default "rpid")

-

-   If string value of an AVP parameter contains only digits, the name of

-   the AVP is int value of the string.

-

-   Finally, the parameters used by sequential forwarding:

-

-     * fr_inv_timer		(default 90)

-     * fr_inv_timer_next	(default 30)

-     * fr_inv_timer_param	(default "")

-     * fr_inv_timer_next_param	(default "")

-

-   Function next_contacts() sets tm fr_inv_timer to fr_inv_timer_next

-   value if, after next contacts, there are still lower qvalue

-   contacts available, and to fr_inv_timer value if next contacts are

-   the last ones left. fr_inv_timer_param can define an AVP

-   overwriting fr_inv_timer value, and similarly, AVP defined by

-   fr_inv_timer_next_param can overwrite fr_inv_timer_next value.

-    _________________________________________________________

-

-1.4. Exported Functions

-

-1.4.1. load_gws()

-

-   Loads URIs of gateways matching RPID AVP (if available) or From URI

-   and user part of Request-URI to gw_uri_avp AVPs.  Returns 1 or -1

-   depending on success.

-

-   Example:

-

-   if (!load_gws()) {

-      sl_send_reply("500", "Server Internal Error - Cannot load gateways");

-      break;

-   };

-

-1.4.2. next_gw()

-

-   If called from a route block, replaces Request-URI by the first

-   gw_uri_avp AVP value and destroys that AVP.

-

-   If called from a failure route block, appends a new branch to request,

-   whose Request-URI is the first gw_uri_avp AVP value, and destroys that

-   AVP.

-

-   Returns 1 on success and -1 if there were no gateways left or if an

-   error occurred (see syslog).

-

-   Must be preceded by successful load_gws() call.

-

-   Example from route block:

-   

-   if (!next_gw()) {

-      sl_send_reply("503", "Service not available - No gateways");

-      break;

-    };

-

-   Example from failure route block:

-

-   if (!next_gw()) {

-      t_reply("503", "Service not available - No more gateways");

-      break;	     

-    };

-

-1.4.3. from_gw()

-

-   Checks if request came from IP address of a gateway.

-

-   Example:

-   

-   if (from_gw()) {

-      ...

-      break;

-   };

-

-1.4.4. to_gw()

-

-   Checks if in-dialog request goes to a gateway.

-

-   Example:

-   

-   if (to_gw()) {

-      ...

-      break;

-   };

-

-1.4.5. load_contacts()

-

-   Loads contacts in destination set in increasing qvalue order as

-   values of lcr_contact AVP.  If all contacts in the destination set

-   have the same qvalue, load_contacts() does not do anything thus

-   minimizing performance impact of sequential forking capability when

-   it is not needed.  Returns 1 if loading of contacts succeeded or

-   there was nothing to do.  Returns -1 on error (see syslog).

-

-   Example:

-

-   if (!load_contacts()) {

-      sl_send_reply("500", "Server Internal Error - Cannot load contacts");

-      break;

-   };

-

-1.4.6. next_contacts()

-

-   If called from a route block, replaces Request-URI with the first

-   lcr_contact AVP value, adds the remaining lcr_contact AVP values with

-   the same qvalue as branches, and destroys those AVPs.  It does

-   nothing if there are no lcr_contact AVPs.  Returns 1 if there were no

-   errors and -1 if an error occurred (see syslog).

-

-   If called from a failure route block, adds the first lcr_contact AVP

-   value and all following lcr_contact AVP values with the same qvalue

-   as new branches to request and destroys those AVPs.  Returns 1 if new

-   branches were successfully added and -1 on error (see syslog) or if

-   there were no more lcr_contact AVPs.

-

-   Must be preceded by successful load_contacts() call.

-

-   Example from route block:

-   

-   if (!next_contacts()) {

-       sl_send_reply("500", "Server Internal Error");

-        break;

-   } else {

-      t_relay();

-   };

-

-   Example from failure route block:

-   

-   if (next_contacts()) {

-       t_relay();

-   };

-

-

-1.5. FIFO Commands

-

-1.5.1. lcr_reload

-

-   Causes lcr module to re-read the contents of gateway table

-   into memory.

-

-1.5.2. lcr_dump

-

-   Causes lcr module to dump the contents of its in-memory gateway

-   table. 

-

-1.6. Known Limitations

-

-   There is an unlikely race condition on lcr reload. If a process uses

-   in memory gw table, which is reloaded at the same time twice through

-   FIFO, the second reload will delete the original table still in use

-   by the process.

-   _________________________________________________________

-

-2.0. TODO

-

-   Function load_gws() currently makes an SQL query for the matching

-   gateways.  In order to avoid the query, also lcr table should be

-   read into memory and the corresponding query should be rewritten in

-   C.

new file mode 100644

@@ -0,0 +1,259 @@

+

+Least Cost Routing Module

+

+Juha Heinanen

+

+Edited by

+

+Juha Heinanen

+

+   Copyright � 2005 Juha Heinanen

+     _________________________________________________________

+

+   Table of Contents

+

+   1. User's Guide

+

+        1.1. Overview

+        1.2. Dependencies

+        1.3. Exported Parameters

+        1.4. Exported Functions

+        1.5. FIFO Commands

+        1.6. Known Limitations

+

+   2. TODO

+     _________________________________________________________

+

+Chapter 1. User's Guide

+

+1.1. Overview

+

+   Least cost routing (LCR) module implements two related capabilities:

+

+   (1) sequential forwarding of a request to one or more gateways

+       (functions load_gws and next_gw),

+

+   (2) sequential forwarding to contacts if they don't share the

+       the same qvalue (functions load_contacts and next_contacts).

+

+   Gateway selection is based on caller's RPID URI (if available in

+   caller's RPID AVP after authentication) or From URI and user part of

+   Request-URI (telephone number).  Gateway patterns matching RPID or

+   From URI and telephone number are ordered for forwarding purpose (1)

+   according to longest user part match, (2) according to priority, and

+   (3) randomly.

+

+   Each gateway belongs to a gateway group either alone or among other

+   gateways.  All gateways in a group share the same priority.

+

+   Gateway and routing information is kept in two tables:  gw and lcr.

+

+   When a gateway is selected, Request-URI is rewritten with information

+   from gw table: URI scheme, prefix, IP address, port, and transport

+   protocol.  Valid URI scheme values are NULL = sip, 1 = sip and 2 =

+   sips.  Prefix is appended in front of Request-URI user part.

+   Currently valid transport protocol values are NULL = none, 1 = udp, 2

+   = tcp, and 3 = tls.

+

+   Table lcr contains prefix of user part of Request-URI, From URI,

+   gateway group id, and priority.  From URI can contain special

+   characters % and _ matching any number of any characters and any one

+   character, respectively.  

+

+   In addition to gw and lcr tables there is third table gw_grp that is

+   used for administrative purposes only to associate names with gateway

+   group ids.

+   _________________________________________________________

+

+1.2. Dependencies

+

+   The module depends on the following modules (in the other

+   words the listed modules must be loaded before this module):

+

+     * tm module

+     * mysql module

+     _________________________________________________________

+

+1.3. Exported Parameters

+

+   LCR module exports the following database related parameters that

+   have usual purpose:

+

+     * db_url (default system default)

+     * gw_table (default "gw")

+     * gw_name_column (default "gw_name")

+     * ip_addr_column (default "ip_addr")

+     * port_column (default "port")

+     * uri_scheme_column (default "uri_scheme")

+     * transport_column (default "transport")

+     * grp_id_column (default "grp_id")

+     * lcr_table (default "lcr")

+     * prefix_column (default "prefix")

+     * from_uri_column (default "from_uri")

+     * priority_column (default "priority")

+

+   In addition there are parameters that can be used to override names

+   of the AVPs used by LCR module:

+

+     * gw_uri_avp	  (default "1400")

+     * contact_avp	  (default "1401")

+     * fr_inv_timer_avp	  (default "fr_inv_timer_avp")

+     * rpid_avp		  (default "rpid")

+

+   If string value of an AVP parameter contains only digits, the name of

+   the AVP is int value of the string.

+

+   Finally, the parameters used by sequential forwarding:

+

+     * fr_inv_timer		(default 90)

+     * fr_inv_timer_next	(default 30)

+     * fr_inv_timer_param	(default "")

+     * fr_inv_timer_next_param	(default "")

+

+   Function next_contacts() sets tm fr_inv_timer to fr_inv_timer_next

+   value if, after next contacts, there are still lower qvalue

+   contacts available, and to fr_inv_timer value if next contacts are

+   the last ones left. fr_inv_timer_param can define an AVP

+   overwriting fr_inv_timer value, and similarly, AVP defined by

+   fr_inv_timer_next_param can overwrite fr_inv_timer_next value.

+    _________________________________________________________

+

+1.4. Exported Functions

+

+1.4.1. load_gws()

+

+   Loads URIs of gateways matching RPID AVP (if available) or From URI

+   and user part of Request-URI to gw_uri_avp AVPs.  Returns 1 or -1

+   depending on success.

+

+   Example:

+

+   if (!load_gws()) {

+      sl_send_reply("500", "Server Internal Error - Cannot load gateways");

+      break;

+   };

+

+1.4.2. next_gw()

+

+   If called from a route block, replaces Request-URI by the first

+   gw_uri_avp AVP value and destroys that AVP.

+

+   If called from a failure route block, appends a new branch to request,

+   whose Request-URI is the first gw_uri_avp AVP value, and destroys that

+   AVP.

+

+   Returns 1 on success and -1 if there were no gateways left or if an

+   error occurred (see syslog).

+

+   Must be preceded by successful load_gws() call.

+

+   Example from route block:

+   

+   if (!next_gw()) {

+      sl_send_reply("503", "Service not available - No gateways");

+      break;

+    };

+

+   Example from failure route block:

+

+   if (!next_gw()) {

+      t_reply("503", "Service not available - No more gateways");

+      break;	     

+    };

+

+1.4.3. from_gw()

+

+   Checks if request came from IP address of a gateway.

+

+   Example:

+   

+   if (from_gw()) {

+      ...

+      break;

+   };

+

+1.4.4. to_gw()

+

+   Checks if in-dialog request goes to a gateway.

+

+   Example:

+   

+   if (to_gw()) {

+      ...

+      break;

+   };

+

+1.4.5. load_contacts()

+

+   Loads contacts in destination set in increasing qvalue order as

+   values of lcr_contact AVP.  If all contacts in the destination set

+   have the same qvalue, load_contacts() does not do anything thus

+   minimizing performance impact of sequential forking capability when

+   it is not needed.  Returns 1 if loading of contacts succeeded or

+   there was nothing to do.  Returns -1 on error (see syslog).

+

+   Example:

+

+   if (!load_contacts()) {

+      sl_send_reply("500", "Server Internal Error - Cannot load contacts");

+      break;

+   };

+

+1.4.6. next_contacts()

+

+   If called from a route block, replaces Request-URI with the first

+   lcr_contact AVP value, adds the remaining lcr_contact AVP values with

+   the same qvalue as branches, and destroys those AVPs.  It does

+   nothing if there are no lcr_contact AVPs.  Returns 1 if there were no

+   errors and -1 if an error occurred (see syslog).

+

+   If called from a failure route block, adds the first lcr_contact AVP

+   value and all following lcr_contact AVP values with the same qvalue

+   as new branches to request and destroys those AVPs.  Returns 1 if new

+   branches were successfully added and -1 on error (see syslog) or if

+   there were no more lcr_contact AVPs.

+

+   Must be preceded by successful load_contacts() call.

+

+   Example from route block:

+   

+   if (!next_contacts()) {

+       sl_send_reply("500", "Server Internal Error");

+        break;

+   } else {

+      t_relay();

+   };

+

+   Example from failure route block:

+   

+   if (next_contacts()) {

+       t_relay();

+   };

+

+

+1.5. FIFO Commands

+

+1.5.1. lcr_reload

+

+   Causes lcr module to re-read the contents of gateway table

+   into memory.

+

+1.5.2. lcr_dump

+

+   Causes lcr module to dump the contents of its in-memory gateway

+   table. 

+

+1.6. Known Limitations

+

+   There is an unlikely race condition on lcr reload. If a process uses

+   in memory gw table, which is reloaded at the same time twice through

+   FIFO, the second reload will delete the original table still in use

+   by the process.

+   _________________________________________________________

+

+2.0. TODO

+

+   Function load_gws() currently makes an SQL query for the matching

+   gateways.  In order to avoid the query, also lcr table should be

+   read into memory and the corresponding query should be rewritten in

+   C.

deleted file mode 100644

@@ -1,259 +0,0 @@

-

-Least Cost Routing Module

-

-Juha Heinanen

-

-Edited by

-

-Juha Heinanen

-

-   Copyright � 2005 Juha Heinanen

-     _________________________________________________________

-

-   Table of Contents

-

-   1. User's Guide

-

-        1.1. Overview

-        1.2. Dependencies

-        1.3. Exported Parameters

-        1.4. Exported Functions

-        1.5. FIFO Commands

-        1.6. Known Limitations

-

-   2. TODO

-     _________________________________________________________

-

-Chapter 1. User's Guide

-

-1.1. Overview

-

-   Least cost routing (LCR) module implements two related capabilities:

-

-   (1) sequential forwarding of a request to one or more gateways

-       (functions load_gws and next_gw),

-

-   (2) sequential forwarding to contacts if they don't share the

-       the same qvalue (functions load_contacts and next_contacts).

-

-   Gateway selection is based on caller's RPID URI (if available in

-   caller's RPID AVP after authentication) or From URI and user part of

-   Request-URI (telephone number).  Gateway patterns matching RPID or

-   From URI and telephone number are ordered for forwarding purpose (1)

-   according to longest user part match, (2) according to priority, and

-   (3) randomly.

-

-   Each gateway belongs to a gateway group either alone or among other

-   gateways.  All gateways in a group share the same priority.

-

-   Gateway and routing information is kept in two tables:  gw and lcr.

-

-   When a gateway is selected, Request-URI is rewritten with information

-   from gw table: URI scheme, prefix, IP address, port, and transport

-   protocol.  Valid URI scheme values are NULL = sip, 1 = sip and 2 =

-   sips.  Prefix is appended in front of Request-URI user part.

-   Currently valid transport protocol values are NULL = none, 1 = udp, 2

-   = tcp, and 3 = tls.

-

-   Table lcr contains prefix of user part of Request-URI, From URI,

-   gateway group id, and priority.  From URI can contain special

-   characters % and _ matching any number of any characters and any one

-   character, respectively.  

-

-   In addition to gw and lcr tables there is third table gw_grp that is

-   used for administrative purposes only to associate names with gateway

-   group ids.

-   _________________________________________________________

-

-1.2. Dependencies

-

-   The module depends on the following modules (in the other

-   words the listed modules must be loaded before this module):

-

-     * tm module

-     * mysql module

-     _________________________________________________________

-

-1.3. Exported Parameters

-

-   LCR module exports the following database related parameters that

-   have usual purpose:

-

-     * db_url (default system default)

-     * gw_table (default "gw")

-     * gw_name_column (default "gw_name")

-     * ip_addr_column (default "ip_addr")

-     * port_column (default "port")

-     * uri_scheme_column (default "uri_scheme")

-     * transport_column (default "transport")

-     * grp_id_column (default "grp_id")

-     * lcr_table (default "lcr")

-     * prefix_column (default "prefix")

-     * from_uri_column (default "from_uri")

-     * priority_column (default "priority")

-

-   In addition there are parameters that can be used to override names

-   of the AVPs used by LCR module:

-

-     * gw_uri_avp	  (default "1400")

-     * contact_avp	  (default "1401")

-     * fr_inv_timer_avp	  (default "fr_inv_timer_avp")

-     * rpid_avp		  (default "rpid")

-

-   If string value of an AVP parameter contains only digits, the name of

-   the AVP is int value of the string.

-

-   Finally, the parameters used by sequential forwarding:

-

-     * fr_inv_timer		(default 90)

-     * fr_inv_timer_next	(default 30)

-     * fr_inv_timer_param	(default "")

-     * fr_inv_timer_next_param	(default "")

-

-   Function next_contacts() sets tm fr_inv_timer to fr_inv_timer_next

-   value if, after next contacts, there are still lower qvalue

-   contacts available, and to fr_inv_timer value if next contacts are

-   the last ones left. fr_inv_timer_param can define an AVP

-   overwriting fr_inv_timer value, and similarly, AVP defined by

-   fr_inv_timer_next_param can overwrite fr_inv_timer_next value.

-    _________________________________________________________

-

-1.4. Exported Functions

-

-1.4.1. load_gws()

-

-   Loads URIs of gateways matching RPID AVP (if available) or From URI

-   and user part of Request-URI to gw_uri_avp AVPs.  Returns 1 or -1

-   depending on success.

-

-   Example:

-

-   if (!load_gws()) {

-      sl_send_reply("500", "Server Internal Error - Cannot load gateways");

-      break;

-   };

-

-1.4.2. next_gw()

-

-   If called from a route block, replaces Request-URI by the first

-   gw_uri_avp AVP value and destroys that AVP.

-

-   If called from a failure route block, appends a new branch to request,

-   whose Request-URI is the first gw_uri_avp AVP value, and destroys that

-   AVP.

-

-   Returns 1 on success and -1 if there were no gateways left or if an

-   error occurred (see syslog).

-

-   Must be preceded by successful load_gws() call.

-

-   Example from route block:

-   

-   if (!next_gw()) {

-      sl_send_reply("503", "Service not available - No gateways");

-      break;

-    };

-

-   Example from failure route block:

-

-   if (!next_gw()) {

-      t_reply("503", "Service not available - No more gateways");

-      break;	     

-    };

-

-1.4.3. from_gw()

-

-   Checks if request came from IP address of a gateway.

-

-   Example:

-   

-   if (from_gw()) {

-      ...

-      break;

-   };

-

-1.4.4. to_gw()

-

-   Checks if in-dialog request goes to a gateway.

-

-   Example:

-   

-   if (to_gw()) {

-      ...

-      break;

-   };

-

-1.4.5. load_contacts()

-

-   Loads contacts in destination set in increasing qvalue order as

-   values of lcr_contact AVP.  If all contacts in the destination set

-   have the same qvalue, load_contacts() does not do anything thus

-   minimizing performance impact of sequential forking capability when

-   it is not needed.  Returns 1 if loading of contacts succeeded or

-   there was nothing to do.  Returns -1 on error (see syslog).

-

-   Example:

-

-   if (!load_contacts()) {

-      sl_send_reply("500", "Server Internal Error - Cannot load contacts");

-      break;

-   };

-

-1.4.6. next_contacts()

-

-   If called from a route block, replaces Request-URI with the first

-   lcr_contact AVP value, adds the remaining lcr_contact AVP values with

-   the same qvalue as branches, and destroys those AVPs.  It does

-   nothing if there are no lcr_contact AVPs.  Returns 1 if there were no

-   errors and -1 if an error occurred (see syslog).

-

-   If called from a failure route block, adds the first lcr_contact AVP

-   value and all following lcr_contact AVP values with the same qvalue

-   as new branches to request and destroys those AVPs.  Returns 1 if new

-   branches were successfully added and -1 on error (see syslog) or if

-   there were no more lcr_contact AVPs.

-

-   Must be preceded by successful load_contacts() call.

-

-   Example from route block:

-   

-   if (!next_contacts()) {

-       sl_send_reply("500", "Server Internal Error");

-        break;

-   } else {

-      t_relay();

-   };

-

-   Example from failure route block:

-   

-   if (next_contacts()) {

-       t_relay();

-   };

-

-

-1.5. FIFO Commands

-

-1.5.1. lcr_reload

-

-   Causes lcr module to re-read the contents of gateway table

-   into memory.

-

-1.5.2. lcr_dump

-

-   Causes lcr module to dump the contents of its in-memory gateway

-   table. 

-

-1.6. Known Limitations

-

-   There is an unlikely race condition on lcr reload. If a process uses

-   in memory gw table, which is reloaded at the same time twice through

-   FIFO, the second reload will delete the original table still in use

-   by the process.

-   _________________________________________________________

-

-2.0. TODO

-

-   Function load_gws() currently makes an SQL query for the matching

-   gateways.  In order to avoid the query, also lcr table should be

-   read into memory and the corresponding query should be rewritten in

-   C.

@@ -103,15 +103,19 @@ Chapter 1. User's Guide

    If string value of an AVP parameter contains only digits, the name of

    the AVP is int value of the string.

-   Finally, there are two parameters used by sequential forwarding:

+   Finally, the parameters used by sequential forwarding:

-     * fr_inv_timer	  (default 90)

-     * fr_inv_timer_next  (default 30)

+     * fr_inv_timer		(default 90)

+     * fr_inv_timer_next	(default 30)

+     * fr_inv_timer_param	(default "")

+     * fr_inv_timer_next_param	(default "")

    Function next_contacts() sets tm fr_inv_timer to fr_inv_timer_next

    value if, after next contacts, there are still lower qvalue

    contacts available, and to fr_inv_timer value if next contacts are

-   the last ones left.

+   the last ones left. fr_inv_timer_param can define an AVP

+   overwriting fr_inv_timer value, and similarly, AVP defined by

+   fr_inv_timer_next_param can overwrite fr_inv_timer_next value.

     _________________________________________________________

 1.4. Exported Functions

@@ -46,19 +46,23 @@ Chapter 1. User's Guide

    Each gateway belongs to a gateway group either alone or among other

    gateways.  All gateways in a group share the same priority.

-   Gateway selection operates on two database tables: gw and lcr.  Table

-   gw contains gw's name, IP address, port, URI scheme, transport URI

-   parameter, and group id.  IP address, URI scheme, and transport are

-   coded as unsigned integers.  Valid URI scheme values are NULL = sip,

-   1 = sip and 2 = sips.  Currently valid transport values are NULL =

-   none, 1 = udp, 2 = tcp, and 3 = tls.

+   Gateway and routing information is kept in two tables:  gw and lcr.

+

+   When a gateway is selected, Request-URI is rewritten with information

+   from gw table: URI scheme, prefix, IP address, port, and transport

+   protocol.  Valid URI scheme values are NULL = sip, 1 = sip and 2 =

+   sips.  Prefix is appended in front of Request-URI user part.

+   Currently valid transport protocol values are NULL = none, 1 = udp, 2

+   = tcp, and 3 = tls.

    Table lcr contains prefix of user part of Request-URI, From URI,

    gateway group id, and priority.  From URI can contain special

    characters % and _ matching any number of any characters and any one

-   character, respectively.  In addition to gw and lcr tables there is

-   third table gw_grp that is used for administrative purposes only to

-   associate names with gateway group ids.

+   character, respectively.  

+

+   In addition to gw and lcr tables there is third table gw_grp that is

+   used for administrative purposes only to associate names with gateway

+   group ids.

    _________________________________________________________

 1.2. Dependencies

@@ -47,13 +47,18 @@ Chapter 1. User's Guide

    gateways.  All gateways in a group share the same priority.

    Gateway selection operates on two database tables: gw and lcr.  Table

-   gw contains gw's name, IP address, port, and group id.  Table lcr

-   contains prefix of user part of Request-URI, From URI, gateway group

-   id, and priority.  From URI can contain special characters % and _

-   matching any number of any characters and any one character,

-   respectively.  In addition to gw and lcr tables there is third table

-   gw_grp that is used for administrative purposes only to associate

-   names with gateway group ids.

+   gw contains gw's name, IP address, port, URI scheme, transport URI

+   parameter, and group id.  IP address, URI scheme, and transport are

+   coded as unsigned integers.  Valid URI scheme values are NULL = sip,

+   1 = sip and 2 = sips.  Currently valid transport values are NULL =

+   none, 1 = udp, 2 = tcp, and 3 = tls.

+

+   Table lcr contains prefix of user part of Request-URI, From URI,

+   gateway group id, and priority.  From URI can contain special

+   characters % and _ matching any number of any characters and any one

+   character, respectively.  In addition to gw and lcr tables there is

+   third table gw_grp that is used for administrative purposes only to

+   associate names with gateway group ids.

    _________________________________________________________

 1.2. Dependencies

@@ -75,6 +80,8 @@ Chapter 1. User's Guide

      * gw_name_column (default "gw_name")

      * ip_addr_column (default "ip_addr")

      * port_column (default "port")