RBSXTR&R11e-LTE6 why just 100M Ethernet?

RouterOS Wireless Networking
1

Hi,
just wanted to upgrade from a CAT4 LTE device to RBSXTR&R11e-LTE6 because it has CAT6 LTE. All over it looks very nice from the specs (even 2 SIM Slots for failover!!)

But i’m really wondering to not find a gigabit ethernet port. I’m just asking why? Why pairing CAT6 LTE together with fast-ethernet and not gigabit?

2

While CAT6 in theory peaks at 300/50 Mbps it is for vast majority of users highly unlikely to see anything near this speed. Mainly due to two reasons:

  1. radio conditions at modem are not ideal. Signal strength decreases with increasing distance from cell tower and even with completely unobstructed Fresnel zone (full LOS without any obstruction even near the line of sight) max obtainable throughput drops well below maximum when distance is greater than a few hundred metres. If there’s some co-channel interference (and in 4G networks there’s always some because 4G is “single frequency network”), SINR drops even further reducing obtainable max throuhput.
  2. cell capacity (which ideally single LTE CAT4 terminal can use up to 100%, higher categories as well) is shared among many users. There are many different scheduling algorithms and MNO decides which one should be used. But most of algorithms are combination of round-robin and max-throughput. In any case, many concurrent cell users will divide cell capacity this way or another and time granularity of sharing is 1ms.

So realistic LTE client installation sharing same cell with a few hundred other users (meaning 10-20 users are active at the same time) will give you anything between 10Mbps and 50Mbps of realistic throughput with peaks exceeding 100Mbps very seldomly. At the same time 100Mbps ethernet works more robust than 1Gbps which means stable ethernet link on longer cable stretches (e.g. when SXT is mounted on a tower or a pole) when 1Gbps might be tripping occasionally.

3

Ok, that’s a reasonable answer. With my actual CAT4 LTE device, which has a gigabit interface, i could measure about 70-90mbps down and 30-50mbps up. Depending on time of course. There is a clear LOS and the tower is just 500meters away. So my plan or wish was to speed it up a little bit by using CAT6. I assume this will not happen with the SXT.

But anyway i like to play with hardware from different vendors and basically there are a few more merits with the SXT such as 2 SIM failover, smaller footprint, RouterOS with a lot of functions and so on.

So i will replace it and wait until some comparable 5G device with gigabit and a reasonable price will be released in the future :smiley:

4

dirks write:

We all wait for new line of devices with m.2 slot to can install any LTE vendors modems… and a PoE-in with 2,5Gb port will be perfect :smiley:

5

And this with a MSP of 150 € :heart_eyes::grin:

6

The CPU in the SXT and LHG maxes out at ~150Mbps with 100% CPU pushing bandwidth on receive only from Btest from the tower connected to my CHR. It might push a little more if it was completely pass through. Add two mangle rules and basic firewall rules, and you’re not doing 100Mbps. Add a queue, and you’d be lucky to get to 70Mbps.

The MIPSBE processor isn’t that strong. ARM, on the other hand, doesn’t have the same issues. So until they make an ARM SXT, it’s all kinda moot.