The first step in joining SCDP is to pick a prefix. This is as simple as adding an entry to the table on the main page and self-assigning a prefix that does not conflict with those already listed. It is recommended that you create a page for yourself so you can share details about your network.

After you've picked a prefix, you will want to choose at least one trunking technology to use for SCDP. Trunking technology support varies among participants, but the following are used in varying degrees:

VPN tunnel required

This trunking method requires a Cisco Integrated Services Router or similar that can support a Channelized T1/E1 Circuit Emulation Module like the NM-CEM-4TE1. This is a close as we can get to a “TDM” trunking experience. However, it does require that you also establish IP peering with the network via VPN tunnel (WireGuard is most common, but other technologies can be supported if needed) and, preferably, BGP.

This will require you to choose a node to peer with. You will want to work through the config with said node operator.

VPN tunnel recommended

This is the preferred trunking method if you have a Cisco Integrated Services Router or other H.323 capable device in your voice network. This is simpler than CEMoIP but is very similar signalling wise to Q.931. However, it does require that you also establish IP peering with the network via VPN tunnel (WireGuard is most common, but other technologies can be supported if needed) and, preferably, BGP. This is because H.323, at least with the common equipment found among the network, is not NAT friendly. If you have a H.323 gateway directly exposed to the Internet, trmg has one exposed that you can peer with which would not require VPN.

VPN tunnel NOT required, but is less fun

If you do not have a device that will speak H.323 or do not want to dive into CEMoIP stuffs, IAX2 is the simplest way (though argubly the least “fun”) to trunk with the network.

We prefer to generally stay away from SIP, but many node operators can support this if needed but it is typically last restort. As of this writing, there are no known node-to-node SIP trunks in service thus no “quick start” instructions for this.

TBD