SIP Carrier Peering: SIP Trunk Group - Media

Data Path Mode Passthru

Determines whether the SBC will transmit media direction (Data Path Mode) received from a peer in the Offer SDP RTP IP.

• Disabled (default)
• Enabled

Late Media Support

Determines whether a SIP late media (reverse offer) INVITE should be converted to a forward offer on egress or else allowed to transparently pass through. Set this flag at the Ingress leg of the Trunk Group.

• Convert (default)
• Passthru

Note: If you configure Packet Service Profile Packet To Packet Control for “Transcode Free Transparency” (see System Provisioning - Packet Service Profile), ensure you also set Late Media Support to Passthru.

Note: When Late Media Support is set to Convert and the Direct Media Allowed flag is enabled for the same call, late media Convert takes precedence for the original egress INVITE being generated. Eventually, the call transitions to a direct media call.

Determines whether the SBC processes multiple audio m-lines, or a combination of audio and image m-lines, in SDP.

• Disabled (default)
• Enabled

Max Ptime Default

This field indicates the default packet size in milliseconds. The value ranges from 10 to 150 and the default value is 150.

Comedia Connection Role

• Active – The SDP offer will include "a=direction: active" attribute line.
• None – The SDP offer will not include a direction attribute line.
• Passive – The SDP offer will include "a=direction: passive" attribute line.

Enable this flag to allow the transmission Medium Requirement Unrestricted 64kbit/s control for SIP-ISUP interworking.

• Disabled (default)
• Enabled

Media IP Interface Group Name

Name of the IP interface group for media.

Each trunk group can have a media IP address configured to specify a specific IP address to use when allocating UDP or TCP media. The default value is 0.0.0.0.

Note: Does not apply to D-SBC.

If you prefer to choose an IP address from a range of values configured in Media Port Range (UDP) or TCP Port Range, set this parameter to the default value.

Configure the Media IP Address as either an IPv4 or IPv6 address (except for H.323, which does not support IPv6 addresses). The configured IP address must belong to the IP Interface Group configured as the Media IP Interface Group for the trunk group. For additional details, refer to SIP over UDP and SIP over TCP.

Source Address Filtering

When enabled, incoming media packets that do not match the expected source IP address and UDP port are filtered out.

• Disabled 
• Enabled (default)

Media Addr Type

The media address type attribute determines the type of IP address the SBC uses in an offer.

• IPv4 – IPv4 address is selected from the media interface group for the SDP, or else call fails.
• IPv6 – IPv6 address is selected from the media interface group for the SDP, or else call fails.
• IPv4 and IPv6 – Both address types are allowed. Additional configuration options are available using the Anat parameters. Refer to Media - Anat.
• Match Sig Addr Type (default) – Selects media IP based on the signaling IP version used for the call. When the SIP peer IP type is known, the media IP will match. When the SIP peer IP version is unknown, the media IP matches the IP version used for signaling (for example, IPv4 first and IPv6 for resolving an FQDN) for the call attempt. When a “Signaling IP version mismatch” results in a collision crank back, the SBC reselects the media IP to match the new signaling IP version.

Note: The Anat parameter page is only available when the IPv4 and IPv6 option is chosen. The Ice parameter page is available only when the IPv4 and IPv6 option is chosen and the Services NAT Traversal option enables Ice Support. Refer to Services - Nat Traversal.

Recordable

Enable this flag to support the media recording of RTP stream to an external recording device on this SIP trunk group.

• Disabled (default)
• Enabled

SDP Attributes Selective Relay

Enable this flag to control the selective relay of unknown SDP attributes at the session level and attributes from the core audio stream.

• Disabled (default) – Session level attributes are dropped. Media stream level attributes are dropped unless from a non-core stream.
• Enabled – All qualified session level and media stream level attributes are relayed, which includes attributes from a= and b= lines.

Enables the MSRP payload relay over TCP connections that will be setup on a successful negotiation of MSRP SDP attributes.

• Disabled
• Enabled (default)

Enable this option to reuse an existing TCP connection with an IP peer for multiple MSRP sessions (MSRP multiplexing). MSRP multiplexing applies only to MSRP sessions established using back-to-back user agent (B2BUA) behavior. Multiplexing cannot be applied to MSRP sessions established based on the RFC 6714 “Connection Establishment for Media Anchoring” (CEMA) type of handling. The options are:

• Disabled (default)
• Enabled

Use this parameter to choose an Address Context realm name to use as the primary realm for this SIP trunk group.

Note: This configuration is not supported on ERE and is intended for use only with an external PSX.

When enabled, SBC sends only the main audio/image stream in the SDP offer.

• Disabled (default)
• Enabled

This flag supports Lync/Desktop sharing application media streams.

• Disabled (default) – lyncShare media streams are not allowed for the specified Trunk Group.
• Enabled – lyncShare media streams are allowed for the specified Trunk Group.

Refer to Configuring SBC and LYNC in Media Environment for configuration details.

When enabled on a trunk group, this flag includes the b=AS attribute in the SDP outgoing offer or answer sent on that trunk group.

• Disabled (default)
• Enabled

This flag does not insert the b=AS SDP attribute for non-audio streams or at the session level. The b=AS SDP attribute does not apply to the H.323 signaling interface.