12 Oct
2020
12 Oct
'20
5:05 p.m.
Phil Karn via 44Net je 11. 10. 20 ob 19:31 napisal:
On 10/11/20 07:36, Janko Mivšek via 44Net wrote:
There was a rush installing DMR repeaters two years ago, that's why
everyone setup a plain WiFi link into public internet to became online
as soon as possible. Now at least in my country we started adding
cross-hill links to achieve redundancy. These are still mostly WiFi but
also homebrew NBP by S53MV. We also started using 44 IPs to harmonize
different networks into a nation-wide one.
I agree and IP Multicast is something we can
afford on our 44net based
networks, which are without NAT and other limits for IPv4 Multicast.
For connecting DMR repeaters between themselves directly, in zero-cong
fashion, for instance. Without need for a central DMR master server,
which itself is a single point of failure. Its sole role can be to
coordinate traffic on talkgroups but the repeater network can learn
and communicate directly afterwards. Specially in case of master
server failure or network split of any kind.
I am especially interested in repeater linking via amateur IP
facilities. As I understand it, most repeater linking is over commercial
Internet connections, which is great except that you can't count on them
being there in emergencies. Besides, we're hams. I don't know DMR's IP-level protocols, but if
they can be multicast, and
the 44-net can support general multicast, that would be a perfect
combination.
All are using unicast UDP. DMR-Multicast protocol is converting them
into its own multicast-aware format.
Janko S57NK
This is an
idea behind a DMR-Multicast project which is already
written and I hope I will start testing to release this winter.
Great!
Phil