Prefix Manipulation Tab
You can configure the SIP Soft Switch to automatically modify destination and origination numbers for inbound and outbound calls that this trunk/gateway handles depending on the prefix and, if needed, the length of the number the caller uses. For example, configure the SIP Soft Switch to automatically insert the long distance prefix/area code to the beginning of an origination number if the caller dialed a local number without the long distance prefix/area code.
Four Prefix Manipulation Examples are provided below the procedure.
To Configure the Prefix Manipulation Tab Settings:
1.On the Management Portal menu window, click System Configuration > SIP Soft Switch > Trunks/Gateways.
2.On the Trunks/Gateways page, click the Trunks/Gateways ID link, then click the Prefix Manipulation tab to configure or verify the following fields. To add a row to any Destination Number/Origination Number section, fill in the fields, then click the green plus sign icon.
•Match fields - These fields are the selection criteria the system uses to determine if an action (such as stripping digits, trimming non-relevant information, and/or inserting digits) needs to be performed on the origination or destination number. The number must match the information specified in both the Prefix and the Number length fields.
•Prefix - The prefix to which the modification applies. Type an asterisk (*) in this field to indicate any prefix.
•Number length - The length of the number dialed. Using number length as match criteria enables the system to differentiate between types of phone numbers (such as internal 3- or 4-digit numbers, 7-digit local numbers, 10-digit long distance numbers, etc.). Type an asterisk (*) in this field to indicate numbers of any length.
•Apply fields - The fields in this section determine how the system will manipulate the destination or origination numbers (stripping digits, trimming non-relevant information, and/or inserting digits).
•Trim after - The system uses the character in this field as a guide for removing non-relevant user information from the SIP initial invitation message, to prevent incorrect routing of a call. For example, by typing a semi-colon (;) in the Trim after field, the system will trim the following invitation from this:
<sip:Peter;[email protected];user=phone>
to this:
<sip:Peter @anycompany.com;user=phone>
•Strip - The number of digits you want the SIP Soft Switch to remove from the beginning of the number (either destination or origination number, depending on which Strip field you configure). This feature is useful for stripping a 9 from a telephone number before sending a call to a gateway.
•Insert - The digits you want the SIP Soft Switch to insert at the beginning of the number.
•Append - The digits you want the SIP Soft Switch to add to the end of the user field. For example, if you used trim after for an incoming call, you may need to append the info trimmed for the outgoing call, changing from this:
<sip:Peter @anycompany.com;user=phone>
to this:
<sip:Peter;[email protected];user=phone>
3.Click the Update button on the tab to apply your changes.
Prefix Manipulation Examples
Example 1: Prefix manipulation for calls placed by SIP Soft Switch to trunk (outgoing calls) The following example demonstrates the use of the Prefix and Insert fields to change a dialed extension to an acceptable number for a PSTN gateway. The outgoing origination number fields convert a caller’s number from a 3-digit extension, starting with 42 (such as 428), to a local PSTN number: 404-1428 (inserting 4041 in front of the 3-digit extension), allowing the PSTN destination to see the entire number.
Origination Number:
Prefix = 42
Number length = *
Insert = 4041
Example 2: Prefix manipulation for calls received by SIP Soft Switch from trunk (incoming calls)The following example demonstrates how to append a 9 to an incoming number to facilitate a subsequent call-back, if needed. The incoming origination number fields insert a 9 at the beginning of the call ID of incoming calls. This enables the call recipient to use the call-return features of the phone, since the call-back number is already configured in the correct format as a result of prefix manipulation settings (otherwise, the call return feature fails). By inserting a 9 for an incoming call such as 777-1234, the sequence of numbers: 9 777-1234, would correctly access the PSTN if the call recipient needs to return the call.
Origination Number:
Prefix = *
Number length = *
Insert = 9
Example 3: Prefix manipulation for calls placed by SIP Soft Switch to trunk (outgoing calls)The following example demonstrates the use of the Number length field. Number length is particularly useful if your end users dial less than the full phone number required to reach a given phone. In this example, multiple dialing scenarios are considered:
|
Number Dialed |
Prefix Manipulation: |
Result |
|
555 1212 |
adds 91925 |
9 1 925 555 1212 |
|
925 555 1212 |
adds 91 |
|
|
9 925 555 1212 |
strips the 9, then adds 91 |
|
|
1 925 555 1212 |
adds 9 |
In the first, the end user dials only 7 digits for a local number (for instance 555-4321), but your carrier requires the full 10 digits (including area code, and the leading 1 to indicate North American long distance). Based on the Prefix Manipulation settings indicated below, the system reconfigures the number to be the full 10 digits required by the local carrier and includes the digit 9, needed for an outside line. In the second scenario, the number dialed is a 10-digit number, for instance (925) 555-4321; the system converts it to a PSTN number preceded by a 9: 9 1 925 555-4321. In the third scenario, the number dialed is an 11-digit local number, for instance 9 (925) 555-4321 (the long-distance prefix was not dialed); the system strips the 9 and inserts the required 9 and 1. In the fourth scenario, the number dialed is an 11-digit local number, for instance 1 (925) 555-4321 (the required 9 for an outside line was not dialed); the system inserts the required 9.
Destination Number:
Prefix = *
Number length = 7
Insert = 91925
Prefix = *
Number length = 10
Insert = 91
Prefix = 9
Number length = 11
Strip = 1
Insert = 91
Prefix = 1
Number length = 11
Insert = 9
Example 4: The following example is a more complicated gateway prefix manipulation configuration, for an environment in which users wanting the highest quality connection can dial 884 before dialing the rest of an outbound number. The 884 prefix routes the call to Gateway 884, which is the best gateway in the environment.
Prefix manipulation for calls placed by SIP Soft Switch to trunk (outgoing calls)
Destination Number:
Prefix = 8849
Number length = *
Strip = 3
Origination Number:
Prefix = *
Number length = *
Insert = 4041
Prefix manipulation for calls received by SIP Soft switch from trunk (incoming calls)
Destination Number:
Prefix = *
Number length = *
Strip = 4
Origination Number:
Prefix = *
Number length = *
Insert = 9
In the prefix manipulation configuration described in Example 4:
•The Outbound Calls Destination Number configuration causes the SIP Soft Switch to strip the first 3 digits from any destination number of an outbound call if the first 4 digits of the destination number are 8849.
•The Outbound Calls Origination Number configuration causes the SIP Soft Switch to insert the digits 4041 to the beginning of the origination number of all outbound calls passing through this gateway.
•The Incoming Calls Destination Number configuration causes the SIP Soft Switch to strip the first 4 digits from the destination number of any incoming call it receives from any gateway or trunk.
•The Incoming Calls Origination Number configuration causes the SIP Soft Switch to insert a 9 at the beginning of the origination number of any incoming call it receives from any gateway or trunk.
The following diagrams use the above sample gateway (Gateway 884) to illustrate how the SIP Soft Switch handles prefix manipulation. The example assumes the dial plan is configured such that users must dial a 9 to place an outbound call, and that the gateways are configured to remove the prefix 9 from outbound calls.
Prefix Manipulation (Outbound):
1.A user at extension 600 calls an external phone at (415)111-2121. The call is important, so the user dials the prefix 884 to ensure the highest quality gateway (Gateway 884) handles the call.
2.The SIP Soft Switch receives the call, strips the digits 884 from the destination number, and prefixes the digits 4041 to the origination number before sending the call to the Gateway 884.
3.Gateway 884 strips the prefix 9 from the destination number, and adds a 1 plus the area code to the origination number before sending the call to the PSTN.
4.The PSTN sends the call to its destination. The caller ID on the readout of the destination phone shows the modified origination number.
Prefix Manipulation (Inbound):
1.An external caller calls an Ivanti Voice user at (925)404-1600. The call goes to the PSTN.
2.The PSTN receives the call and passes it to the Ivanti Voice gateway configured to receive incoming calls.
3.The gateway strips the first four digits (1925) from the destination number and sends the call to the SIP Soft Switch.
4.The SIP Soft Switch strips the first four remaining digits (4041) from the destination number, adds a 9 to the origination number, and sends the call to the Ivanti Voice user.