One of the main distinguishing feature of BrandMeister DMR is that the network is accessible from any master. Therefore you have a choice of 40+ master servers to connect your repeater or hotspot. How to choose?
The best performance will not always be with the master server that is closest to you geographically. Rather, it depends on your internet service provider’s capacity/peerings and the one of the master server.
The key factors for best DMR performance are jitter, then latency. Below is the most simple method to find the best master for you, without any special software.
Step 1: Go to the Brandmeister DMR Master Servers list, and select which master(s) you want to consider. Click on the “Status” button and grab the IP address for the master in your browser’s address bar.
Step 2: From the same network as your repeater or hotspot, run a “ping” command for 1 to 2 minutes to each master you are considering. Perform this test during the time of the day where your typically have the most traffic.
Step 3: Check that the round-trip delay provided by each ping (called latency) stays consistent, without any major variations (called jitter). See the examples below:
Good (No Jitter):
~ ping -t 74.91.118.251
Pinging 74.91.118.251 with 32 bytes of data:
Reply from 74.91.118.251: bytes=32 time=71ms TTL=54
Reply from 74.91.118.251: bytes=32 time=73ms TTL=54
Reply from 74.91.118.251: bytes=32 time=69ms TTL=54
Reply from 74.91.118.251: bytes=32 time=68ms TTL=54
Reply from 74.91.118.251: bytes=32 time=71ms TTL=54
Reply from 74.91.118.251: bytes=32 time=74ms TTL=54
Reply from 74.91.118.251: bytes=32 time=70ms TTL=54
Reply from 74.91.118.251: bytes=32 time=69ms TTL=54
Reply from 74.91.118.251: bytes=32 time=69ms TTL=54
Reply from 74.91.118.251: bytes=32 time=68ms TTL=54
Reply from 74.91.118.251: bytes=32 time=69ms TTL=54
Reply from 74.91.118.251: bytes=32 time=69ms TTL=54
Reply from 74.91.118.251: bytes=32 time=70ms TTL=54
Reply from 74.91.118.251: bytes=32 time=72ms TTL=54
Reply from 74.91.118.251: bytes=32 time=70ms TTL=54
You can see that there are no major latency variations.
Bad (Jitter):
~ ping -t 74.91.118.251
Pinging 74.91.118.251 with 32 bytes of data:
Reply from 74.91.118.251: bytes=32 time=71ms TTL=54
Reply from 74.91.118.251: bytes=32 time=73ms TTL=54
Reply from 74.91.118.251: bytes=32 time=354ms TTL=54
Reply from 74.91.118.251: bytes=32 time=366ms TTL=54
Reply from 74.91.118.251: bytes=32 time=219ms TTL=54
Reply from 74.91.118.251: bytes=32 time=72ms TTL=54
Reply from 74.91.118.251: bytes=32 time=70ms TTL=54
Reply from 74.91.118.251: bytes=32 time=77ms TTL=54
Reply from 74.91.118.251: bytes=32 time=983ms TTL=54
Reply from 74.91.118.251: bytes=32 time=875ms TTL=54
Reply from 74.91.118.251: bytes=32 time=917ms TTL=54
Reply from 74.91.118.251: bytes=32 time=75ms TTL=54
Reply from 74.91.118.251: bytes=32 time=72ms TTL=54
Reply from 74.91.118.251: bytes=32 time=819ms TTL=54
Reply from 74.91.118.251: bytes=32 time=668ms TTL=54
You can observe here the big variances in latency, indicating jitter. Symptoms of jitter include choppy/garbled audio and delayed/dropped transmissions.
Step 4:
Once you have found some masters with no jitter, pick the one offering the lowest latency (smallest ping time).
For any further question, please refer to the BrandMeister Support Portal.
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