I have moved house and the new home only has 10-15Mbs ADSL so I have decided to run everything on 4G. I had a spare v2862Ln so popped in an O2 and speed tests are around 40-50Mbs download. However if I run the same speed test on my iPhone Xs placed next to the router then I can get around 130Mbs. Why such a difference in performance? Also, does anyone know if the LTE modem is faster/better in the v2865Lac as I might consider upgrading?

Just to answer my own question...

The v2862 has LTE category 4 which is 150/50Mbs and the v2865 has LTE category 6 which is 300/50Mbs.

Not sure why there is such a difference between the iPhone and Draytek though still.

Carrier Aggregation (4G+) makes a big difference to performance with LTE, Cat4 modems can't do it unfortunately. The later Cat6 modems in the Vigor 2927Lac & 2865Lac can do CA. In my testing I've seen LTE category 6 make a big difference over cat4. Probably because the bands are not huge, being able to use Band 1 and Band 3 can just about double performance over Band 1 alone.

Even then, the modems in mobile phones are quite different from the modems used in a router, with different cooling constraints and typical use patterns. For example your iPhone X is LTE Category 12, giving up to '600mbps' potentially, but that would normally be in short bursts.

admin3 wrote:
Carrier Aggregation (4G+) makes a big difference to performance with LTE, Cat4 modems can't do it unfortunately. The later Cat6 modems in the Vigor 2927Lac & 2865Lac can do CA. In my testing I've seen LTE category 6 make a big difference over cat4. Probably because the bands are not huge, being able to use Band 1 and Band 3 can just about double performance over Band 1 alone.

Even then, the modems in mobile phones are quite different from the modems used in a router, with different cooling constraints and typical use patterns. For example your iPhone X is LTE Category 12, giving up to '600mbps' potentially, but that would normally be in short bursts.

Really useful info thanks. I have ordered a v2865Lac so will post back with the difference in speed tests.

I have also ordered one of these just out of interest to see if it helps...

Well I was very excited to open my deliveries today but it quickly turned to disappointment.

First the LTE antenna arrived so I tried that on the 2862Ln and on average I would say I got a 10-15% speed boost which isn't great.

Next up the v2865Lac arrived, I did a config backup and restore from the 2862Ln, connected up and ran a speed test. The speed was actually about 10% slower than the 2862 on average during testing.

The O2 mast is very close so I don't understand how a router advertising LTE speeds of 300Mbs can struggle to break the 40Mbs barrier?

Strange, you could check Syslog to see which bands the router is using with the O2 SIM, it looks like they do support carrier aggregation, so the router should list 2 bands when connecting.

Try the stock LTE antennas as well, the frequency ranges used by 4G LTE are quite diverse and a high gain antenna might not be tuned for all of those frequencies. Specifically the 2ghz+ range would see some notable loss with a long/thin enough cable - the stock 1 meter extension and standard antennas might do better there.

Regarding the speed, the upper limit claim is theoretical max similar to wireless LAN performance, the overheads, signal attenuation and shared bandwidth in real world use have a significant impact on speeds. Even the time of day that you're testing can make a big difference.