The ID-1 in DD mode is an Ethernet radio bridge that encapulates Ethernet frames in callsigns. The radios themselves support one to one "simplex" sessions- one call sign to another. If you are talking to the Icom DD Repeater module, the Ethernet on the back of the controller can support any number of ID-1 sessions. We use the older RP-1D modules and the idea is there is a Linux machine sitting behind the repeater controller. When the ID-1s come into the "repeater" (it's simplex) the cpmputers behind each remote ID-1 have a unique IP address and the use of DNAT allows the Linux box to support any to any connections between computers behind ID-1s. If you have an Internet gateway on the Linux box (not very legal for routine use) any number of remote ID-1 connected users can share it. The ID-1 does not know about IP addresses, and we have tested the use of 1 ID-1 to support several PCs behind it.
ID-1 DD mode tips:
1. No streaming - on DD IP voice is not good, esp. 2 way. The radio itself does voice (DV Mode). DD mode is better for TCP traffic like web applications. For UDP streaming use 802.11 gear.
2. It's simplex.
3. Anything the Ethernet sees on the ID-1 goes over the air- so don't put it on a busy switch in a van etc- it will saturate your air link with trash- you have a 90kbps air link to preserve - protect your links. Windows Update is not your friend here.
4. Yes you can go to the Internet - it works- but it's not legal. Think autopatch- limited emergency use
5. Encryption works fine - see #4
6. If the RF path is working the radios spring to life and start chatting - the Ethernet comes up - you see the flashing call signs and up and down arrows
7. The radios themselves are not aware of IP addresses - only the computers at each end
8. Lousy antennas and high loss connectors are not your friends here
9. You can use DHCP- we don't - ID-1s don't use IP addresses
10. Served agency internal web apps work great - note many are encrypted (SSL etc). One idea is to build a non encrypted proxy for the ID-1 users.
11. We use the DD repeaters more like satellites- we have them in nice sites (don't need Internet) and we have tiny web apps like Citadel and our data base for missing persons tracking /hospital ops) on each system, We ignore Internet outages.
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