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SH3 SLow speeds in modem mode

stumac1506
Tuning in

Hi,

I have a SH3 which I have used in Modem Mode for a couple of years on the M200 service and would constantly hit speeds of 210Mbs+.  The SH3 is connected to my internal network through a Ubiquiti USG and has been reliable throughout the time I have had this setup. Even on Wi-Fi I was obtaining speeds of 200Mb using the UAP-AC-Pro access points.

I have recently upgraded to 600Mb and without changing any configuration, my speed dropped from 200+ to a maximum of 130.  Today, I reset the SH3 twice putting it back into router mode and after the 2nd reset, I achieved a download speed of around 640.  However, when I returned the SH3 to Modem mode, the speed dropped back down to 130.  This is extremely frustrating, and I can't see how upgrading the service can reduce the speed in Modem mode.  All connections on the internal network are Cat6 or OM3 fibre to the switches

Any help or advice will be gratefully received.

Thanks,

Stu.

5 REPLIES 5

legacy1
Alessandro Volta
You need a better USG

Test speed with a PC to the hub in modem mode
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I did try the PC to the hub in modem mode and the results were the same. PC to hub in router mode did eventually hit 650 after 2 resets, but the fact remains that I was achieving 220 before the upgrade and with no changes it dropped to 120 after the upgrade.

I don't think that the USG is the issue as the ports are configured to 1Gb

Ok so copy the PC MAC to your USG WAN interface and see what happens
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So, I was about to try your suggestion of copying the MAC address, but tried a speed test first and everything is working the way is should now. No config changes have been made since my previous attempt, but now I'm getting the full bandwidth with 630Mbps.

The SH3 is back in modem mode and the rest of the internal network is as it was.

Threatening to do MAC copying did the trick.🤐

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