Creating and Modifying SIP Signaling Groups

Specifies the admin state of the Signaling group.

• Enable: Enables the signaling group.
• Disable: Disables the signaling group.
• Drain: When Drain is selected, calls that are currently up remain connected. However, new calls and forking are not allowed for the Signaling Group. This allows all the calls to be drained from the SG.

Specifies the Time-To-Live (TTL) value for inbound registration. Inbound registration values should be equal to or greater than this. Valid entry: Enter a value in seconds. Default value: 3600.

This field is visible when the Agent Type is set as Access Mode.

Specifies the SIP Server Table to be used in the Signaling Group. The options in this field are derived from the configuration of SIP Server tables, see Creating and Modifying Entries in SIP Server Tables.

If a SIP Server Table is added which includes a server that has Stagger Registration enabled, Stagger Registration occurs. Also, if a SIP server table is removed which included a server that had Stagger Registration enabled, Stagger Un-registration occurs. For more information about Stagger Registration, see Creating and Modifying Entries in SIP Server Tables .

If you select an entry in the SIP Server table that is defined as DNS SRV, the Load Balancing field is not visible. See Load Balancing.

Specifies the method that Call Control uses to allocate SIP channels.

• • Standard: Specifies the first available low-numbered channel.
  • Reverse Standard: Specifies the last available high-numbered channel.
  • Round Robin: Specifies channels based on next available from low numbered to high numbered.
  • Least Idle: Specifies that channels are chosen based on the least idle channel.
  • Most Idle: Specifies that channels are chosen based on the most idle channel.

Indicates whether or not incoming request messages are challenged for security purposes. If this option is set to Enable, you must specify a realm and at least one entry in the Authorization Table.

• • True: All requests are challenged for the realm, user, and password.
  • False: No request messages are challenged.

Timer indicates the amount of time to wait after receiving a “100 Trying” for a call attempt (egress INVITE). When the timer expires the call will not proceed.

Option: 24 - 750 seconds.

When this field is set to Disabled, only SIP Options (if configured) are used as a keep-alive mechanism to mark the Signaling group as up or down.

When enabled, the SBC Edge ignore a forked leg (disconnect) if that leg is going to a voicemail box, but the rest of the forked legs may connect to the subscriber's other numbers. For details, refer to Forked Calls Answered To Soon (Disconnect on Quick Connect).

Possible entries:

• • Enabled: The forked leg is ignored (disconnected) if that leg is going to a voicemail box, but the rest of the forked legs may connect to the subscriber's other numbers.
  • Disabled. The forked leg is not ignored (disconnected) if that leg is going to a voicemail box.

This field is available only when Forked Call Answered Too Soon is Enabled.

Specifies the timer for the forked leg to be disconnected. Valid entry: 1 - 5000 ms.

For SIPREC, enables or disables the SIP Recording functionality on the selected signaling group.

Select from the drop down list.

• • Enabled: Enables voice recording on the selected Signaling Group.
  • Disabled: Disables voice recording on the selected Signaling Group.

When SIPREC is enabled for the specific Signaling Group, this field enables the selection of an entry from a SIP Recording Table.  Select from the drop down list. This list is populated from the entries configured in the SIP Recording table. For details, refer to Creating and Modifying Entries in the SIP Recorder Table.

This field is available only when SIPRecording Status is set to Enabled.

Determines the streaming mode for audio, fax, and media transmission. This feature requires a video license.

• • Proxy: the video/application stream is processed using the SBC internal processing resources.
  • Direct: the video/application stream is passed directly from one compatible end-point to another; this operation uses neither SBC processor.
  • Disabled: the route is not used for video calls.

The first two options are enabled by default.

Click to see more information about this topic.

• Always on 180 (applies to 180/Alert only) or Always on 180/183 (applies to 180/Alert and 183/Progress): SBC provides ringback, ignoring any arriving in-band media.
  
  • For SIP-originated call legs, 180 is sent to permit SBC to provide in-band ringback via early media.

  • For ISDN-originated call legs, ALERT+PI will be sent along with SBC-inband ringing.

Click to see more information about this topic.

• Never: SBC does not provide ringback and cuts through ringback from the source when/if it arrives.
  
  • With NEVER, SBC will send 180/ALERT to the originating call leg without SDP/PI as in this configuration SBC will not supply inband ringback.

Click to see more information about this topic.

Note: The Play Ring Back setting is activated only after the channel receives an ALERT or 180 Ringing. Issues with ringback and 183 Session Progress must be addressed using a Message Translation.

Click to see more information about Activating Play Ring Back.

Specifies whether a congestion tone plays when a 503 response with reason header Q.850 and cause code = 42 is received for outbound INVITE.

Options: Enable (congestion tone is plays) or Disable (default; congestion tone does not play).

Specifies whether a congestion tone plays when a 503 response with reason header Q.850 and cause code = 42 is received for outbound INVITE.

Options: Enable (congestion tone is plays) or Disable (default; congestion tone does not play).

Specifies whether to send a SIP 183 response immediately after receiving an Invite message. The early 183 Session Progress with SDP provides the SRTP key that will be used to decrypt the transmit stream from SBC to the SIP peer. This setting is used to prevent the peer device (e.g. Mediation server) from staying in the Trying state. This setting is required for Lync 2010/2013 Skype for Business interoperability.

Early 183 is applicable only when Audio/Fax Stream DSP Mode is enabled as the media mode.

The field enables Music on Hold at the SIP Signaling group level. Available options:

• • Always Enabled: Enables local Music on Hold (for SDP attribute “sendonly” or “inactive”).
  • Enabled for SDP Inactive: Enables local Music on Hold when there is no possibility of the peer device sending its own music during hold (for SDP attribute “inactive”).
  • Disabled: Disables Music on Hold for the SIP Signaling Group.

Default value: Disabled.

For detailed information about enabling Music On Hold as part of the Media configuration, see Configuring the Media System. For detailed information about uploading music files, see Uploading Music on Hold Files - SBC Edge.

Media Codec Latch allows enabling or disabling of the codec lockdown when receiving multiple codecs in offer answer model.

When disabling Media Codec Latch, the SBC will not renegotiate the codec if the peer sends more than one codec in the answer. 

Valid entries: Enable or Disable

Default value: Enable

Each SIP-SG is configurable with the DSCP value to be used for signaling. This allows for improved quality of service in real-time applications, such as conferencing and conversations. The settings take effect for both client and server modes of SIP. The default value of 40 is the most common value used in the VOIP networks for signaling packets. The configured value should be chosen according to the QoS policies of the IP network in which the signaling packets travel.

Valid entry range: 0 to 63 (inclusive). Default value: 40.

Specifies the Interactive Connection Establishment (ICE) Mode that is enabled/disabled. This field is displayed only when ICE Support is enabled.

For SBC 1000/2000:

Two ICE Modes are available:

• • Lite: The SBC operates as an ICE-Lite agent endpoint (for SIP calls involving NAT devices) with a full ICE agent in the role of controlling agent. 
  • Full: The SBC operates as an ICE (full) agent endpoint. 

• • Lite: For the SBC SWe Lite, only Lite mode is supported. The SBC operates as an ICE-Lite agent endpoint (for SIP calls involving NAT devices) with a full ICE agent in the role of controlling agent. 

Enables and disables NAT Traversal detection for inbound SIP/RTP packets.

• • When detection is disabled, none of the following fields are visible.

Specifies netmask used to compare the SIP Signaling IP and the RTP IP used for latching.

• • The Source Media Netmask field is present if Inbound NAT Transversal Detection and Secure Media Latching are enabled.
  • The netmask must be specified in dotted decimal format (e.g., 255.255.255.255).

Specifies a maximum time to live (TTL) for the SIP registration. The SBC uses this feature to determine that the client is still active, and aid in keeping bindings to remote NAT devices alive. If the SBC does not receive a request to re-register from the client before the expiry, the call and the registration are torn down.

• • Note that this field is only applicable to clients registering from behind NAT devices.
  • Setting the Max. TTL to a low duration may result in excessively high system resource usage as the number of NAT clients increases.

Specifies how the Signaling Group will select the local IP.

• • Auto: Means that the SBC connects to the peer and queries the local IP which is used in SIP headers and SDP.
  • Bind: Binds to a specified interface and uses that IP address (1st/2nd) in headers and SDP.

Specifies the public IP of the NAT server visible from Internet. The NAT server's ports must be configured to allow SIP and RTP traffic, for example: port range 5060-5061 for SIP and 16000-17000 for RTP.

The IP address specified in this field must be publicly accessible.

If TLS is selected this specifies the TLS Profile that the TLS port uses for secure SIP messages.

Note: When several TLS Signaling Groups are all listening on the same port (for example, 5067), you must use the same TLS profile. If you need different TLS profiles, the Signaling Groups must listen on a different port.

Specifies the IP Address (IPv4 or IPv6) or Fully Qualified Domain Name of a server from which the SBC will accept SIP messages. Federated IP allows IPv4, IPv6, or FQDN address format.

For IPv4:

• If the Netmask is not specified, 255.255.255.255 is used.
• When an IP Address is specified the Netmask is mandatory.

For IPv6:

• Prefix format is used to identify the subnet.

For FQDN:

• When an FQDN is specified, all the IPs in that domain are added.
• Uses the Federated IP Netmask/Prefix field to determine whether the signaling group uses IPv4 or IPv6.

For IPv4: Specifies the network address mask to apply against the specified server address.

For IPv6: Specifies the prefix to identify the subnet.

This option enables or disables the ability for the SBC to manipulate SIP messages using previously configured Message Tables.

Select from the drop-down list: Enable (enables the feature) or Disable (disables the feature).

The rules in this table are used to manipulate inbound SIP messages in the Signaling Group. The Signaling Group will support a maximum of 10 Message Rule Tools allowed in the Signaling Group (inbound direction).

• • Up: Moves the message table entry up in the list.The rules are applied in the order the tables are listed.
  • Down: Moves the message table entry down in the list.The rules are applied in the order the tables are listed.
  • Add: Displays a drop-down list of available message tables. Select an entry and click Apply.
  • Remove: Removes the message table entry from the list.

The rules in this table are used to manipulate outbound SIP messages in the Signaling Group. The Signaling Group will support a maximum of 10 Message Rule Tools allowed in the Signaling Group (outbound direction).

• • Up: Moves the message table entry up in the list. The rules are applied in the order the tables are listed.
  • Down: Moves the message table entry down in the list.The rules are applied in the order the tables are listed.
  • Add: Displays a drop-down list of available Message Tables. Select an entry and click Apply.
  • Remove: Removes the message table entry from the list.