In this section:

 

The NAT Direct Media Group is a collection of public signaling IP addresses for NAT devices supporting Direct Media (DM). A NAT Direct Media Group name can be maximum of 32 characters; however, “0.0.0.0” (IPv4) and “::0” (IPv6) are not allowed.

For the SBC to support direct media between NAT and non-NAT endpoints, the NAT router used in the call must have SIP Application Level Gateway (ALG) functionality for the media to flow between end points.

To allow Direct Media between NAT devices, or between NAT and Non-NAT devices, the following configuration is necessary.

  1. Enable directMediaAllowedBehindNAPT and DM flags at the Trunk Group level.
  2. For Direct Media between endpoints behind same NAT, ensure the signaling IPs of the endpoints match.
  3. For Direct Media across NAT devices, or from NAT to Non-NAT (Hybrid Networks), configure/group the Signaling IPs of the NAT or Non-NAT device (for Hybrid networks) in the new NAT Direct Media Group table at the Address Context level.

Direct Media is disallowed under following conditions:

  • One or both endpoints are behind NAT and directMediaAllowedBehindNAPT flag is disabled.
  • If directMediaAllowedBehindNAPT flag is enabled and Signaling IPs of the NAT devices do not match.
  • Signaling IPs of the NAT or Non-NAT (for Hybrid Networks) devices are not grouped in the same NAT Direct Media Group Table.
  • Address Context name of both endpoints do not match.
  • If the call is a Lawful Intercept call.

Command Syntax

The CLI syntax to enable Direct Media with NAPT at  the trunk group level is shown below (refer Zone - SIP Trunk Group - CLI for details):

% set addressContext <name> zone <name> sipTrunkGroup <TG-Name> media directMediaAllowedBehindNapt <disable | enable>

 

The CLI syntax to group the endpoint signaling IP addresses for which to allow Direct Media with NAPT is shown below:

% set addressContext <name> natDirectMediaGroup <groupName> dmNatPrefix <IpV4_Address> <prefix_length>

Command Parameters

NAT Direct Media Group Parameters

Parameter

Length/Range

Description

natDirectMediaGroup

1-23

The name of the group of signaling IP addresses for NAT devices supporting Direct Media residing in NAPT Qualification Table.

dmNatPrefix

N/A

Grouped public signaling IP addresses of NAT devices that allow direct media. This field consists of an IP address and prefix as specified below:

  • <IP_address> – The public signaling IPv4 or IPv6 address of this prefix.

    NOTE: IP address  “0.0.0.0” (or any IP address ending in "0") is not allowed in this configuration.

  • <prefix_length> – The length (in bits) of the prefix. (IPv4 length: 1-32. IPv6 length: 1-128).

 

Command Examples

% show addressContext ADDRESS_CONTEXT_1 natDirectMediaGroup
natDirectMediaGroup DM_GROUP_1{
    dmNatPrefix 10.70.52.91 32;
    dmNatPrefix 10.70.52.127 32;
    dmNatPrefix 10.70.52.143 32;
}
% show addressContext ADDRESS_CONTEXT_1 natDirectMediaGroup
natDirectMediaGroup DM_GROUP_2{
    dmNatPrefix 10.70.52.92 32;
    dmNatPrefix 10.70.52.127 32;
}

  • No labels