SIP Signaling - SIP

The IMG 2020 supports the SIP protocol as described in RFC 3261. To configure the IMG 2020 to process calls using the SIP protocol, a SIP Stack must first be created. The SIP stack must be created on each IMG 2020 node to be able to process SIP signaling on it. The SIP stack can be configured to have one IP address service it or can be configured to have up to 20 IP addresses service it. The SIP object creates and configures the attributes of the SIP stack. Once the attributes have been configured, the IP addresses that will service the stack need to be configured. This is achieved through the SIP IP Address object configured beneath the SIP object. Refer to the information below.

Web GUI Page

Dialogic > IMG 2020 > Signaling > New SIP  

Open

Max SIP Signaling objects

One SIP Signaling object per IMG 2020 Node.

Related Topics and Dependencies

A separate SIP stack must be created for each individual Physical IMG 2020 (IMG 2020) node. One important feature configured in the SIP stack is whether the SIP stack is serviced by one or multiple SIP IP Addresses. This is configured in the IP Operation Mode field. If Single IP is selected then only one IP address can be configured to service the SIP stack. If Multiple IP is selected, up to 20 IP addresses can be configured to service the SIP stack. Before creating the SIP object, the Logical Interface and IP Address object under it must be configured with IP addresses created as Service IP addresses. Refer to the links below for more information

Signaling

SIP Overview

Multiple SIP Addresses - Overview

Configure SIP (Single SIP IP)

Configure SIP (Multiple SIP IP)   

Field Descriptions

Compact Header

The IMG 2020 can be configured to represent the SIP Headers in either a non-abbreviated standard form or an abbreviated form. The abbreviated form is useful when messages become too large to be carried on the transport available to it. A compact form may be substituted for the longer of a header field name without changing the semantics of the message. Select from drop down menu whether to enable or disable the shorter form. See below.

Enable - If enabled is selected, the SIP message will be an abbreviated message according to RFC 3261 Sec 7.3.3 Compact Form. A wireless application where bandwidth needs to be limited is a good reason for using compact headers.

Disable - If disabled, the SIP message will send non-abbreviated messages.

Message Restriction Setting

The configuration settings in the Message Restriction Setting field can impose a maximum length to any incoming SIP message as well as any incoming SIP Headers. Along with maximum lengths, it can also impose the maximum number of Headers that can be contained in a SIP message. The two selections in the drop down menu are Default or Option 1. Select from drop down menu whether the restrictions will be imposed.

Default - The SIP messaging will not have any size limits imposed. Refer to the SIP Message and Header Restrictions topic for a table displaying the limits and restrictions imposed when Default selected.

Option 1 - The IMG 2020 will impose limits to the size of its SIP messages as well as size limits to the individual SIP Headers on the incoming leg. Refer to the SIP Message and Header Restrictions topic for a table displaying the limits and restrictions imposed when Option 1 is selected.   as well as a table displaying the normal limits to both the Default and Option 1 settings.

UserName (AOR)

A SIP Identifier, Public Address, or Address of Record (AOR) specifies the To: and From: URI user part that will be used in any outbound messaging. This field defaults to: DIALOGIC-BDN. To modify, click in the Username (AOR) field and enter a different username. This field is commonly referred to as Public Address.

Authentication UserName

Username used for authentication to guard against hijacking. To add a username, click in the Authentication Username field and enter username.

Authentication Password

Password used for authentication to guard against hijacking. To add a password, click in the Authentication Password field and enter a password.

SIP-T Enabled

SIP-T is a mechanism used to interwork ISUP messaging from the PSTN into SIP messaging for transport through a SIP network. SIP-T allows traditional ISUP parameters to originate in an ISUP network, transport those messages across SIP Network using UDP, TCP, or TLS and then terminate in a second ISUP Network. To configure SIP-T on the IMG 2020 select either Yes or No from drop down menu.

No (Default) - Do not inter-work ISUP messaging into SIP-T format for transport.

Yes - Inter-work ISUP messaging into SIP-T format for transport.

For configuration information, refer to the Configure SIP to SIP-T Interworking topic.

SIP-T Behavior

This field defaults to Not Used when the SIP-T Enabled field above is set to No. When SIP-T Enabled is set to yes, this field can be modified. See selections below for when the SIP-T Enabled field above is set to Yes.

Optional - Optional is the default. If Optional is selected, and the far end does not support SIP-T, the call will not be released.

Required - If Required is selected, and the far end does not support SIP-T, the call will be released.

IP Operation Mode

Single IP (Default) - The Single IP selection puts the SIP Signaling stack into Single IP mode. In this mode, one external network can communicate with the SIP stack through one of the interfaces on the rear of the IMG 2020. This mode is used for backwards compatibility with existing configurations and for a few features that require a single IP address configured to communicate with the SIP stack.

Multiple IP - The Multiple IP selection puts the SIP Signaling stack into Multiple IP mode. In this mode, up to 20 IP addresses can be configured to communicate with the SIP stack. Each of the interfaces can be configured with a different network IP address so the SIP stack on the IMG 2020 can communicate with multiple external networks. Refer to the Multiple SIP Addresses - Overview topic for more information on the Multi SIP IP Address feature.

Incoming UAC Routing

IP address and port (Default) - When set to IP address and port, the IMG 2020 will enforce incoming UAC routing based on IP address as well as port.

IP address only - When set to IP address only, the IMG 2020 will enforce incoming UAC routing only using the IP address. Therefore, different UAC with same IP address and different port can be used to send request to the IMG 2020.

Retry-After (# of Seconds)

The number of seconds (1 - 65535 seconds) the IMG 2020 will inform a remote inbound gateway to wait before re-sending a SIP INVITE message. The IMG 2020 informs the remote gateway by use of the Retry-After Header Field in its response.  See SIP Retry-After Header - Transmit -or- SIP Retry-After Header - Receive for more information. To modify the Retry-After field either click in the Seconds box and enter the number of seconds to wait or use the sliding scale to modify.