Introduction
The variances among SIP networks, such as incompatible interconnection, can disrupt SIP operations. In order to resolve these problems, Edge Server provides SIP Header Manipulation, giving Edge operators the ability to control SIP traffic by manipulating SIP messages. Shortly, Manipulation is to modify SIP Header.
Functions
- Add custom SIP Header, Parameters
- Capture information from a message and insert it into another message
- Remove all custom SIP headers
- Execute the change if the condition is satisfied
- Drop call or Log message if the condition is not satisfied
Contract
- Manipulation rule is only applicable to Outbound Trunk.
- Manipulation rule has a restriction to protect Edge Function, which does not allow to modify native SIP Header or native Session Variable.
- X-EDGE and V-EDGE are reserved for Edge and not available to modify.
- X- indicates custom SIP Header
- V- indicates custom Session Variable
Parameters
| Parameter | Role | Description |
|---|---|---|
| Conditions | Optional | Conditions are the set of conditions (max 5 rules) that will be used to decide which action to be performed in Statements or Else Statement. If no conditions is set, it means always matches > always trigger actions in Statements. |
| Statements | Required | Sequence of actions (max 5 rules) to perform if conditions match. |
| Else Statement | Optional | Sequence of actions (max 3 rules) to perform if conditions do not match. |
1. Conditions
| Parameter | Role | Description |
|---|---|---|
| variable | Required | Session Variable or SIP Header, SIP Params |
| pattern | Required | The regex is used to define a search pattern |
2. Statements
| Parameter | Role | Description |
|---|---|---|
| reference | Optional | Session Variable or SIP Header, SIP Params |
| pattern | Optional | The regex is used to define a search pattern |
| target | Required | New Variable (V-) or new Header (X-) |
| values | Required | The list of values which can be fix chars, or back-reference from reference with pattern |
3. Else Statement
| Parameter | Role | Description |
|---|---|---|
| action | Required | 2 available actions:Log: add log message (can be used to monitor/alert)Drop: hang up the call |
| param | Required | String base, depending on the value of action:Message content for logHangup reason for drop |
The pattern must follow Perl Compatible Regular Expressions (PCRE) syntax.
Syntax Description
The below table shows most formalisms provide the following operations to construct regular expressions.
