Telkom Tower LTE Access Denied - For The Experts

[heinjhgrobler]

Hello to all network experts... Perhaps one could help me to get my problem resolved.

I am new to Telkom mobile, running on a 2TB uncapped LTE package. Since I've recieved my Telkom sim-card via couriers about 2 months ago I have had intermittent network connection.

I run the simcard via a MikroTik routor on my house's roof through a Hauwei WiFi router inside the house.

Im a bit on the edge of the network coverage but with the directional MikroTik router I have good to excellent signal from the Telkom tower in my area.

The problem is that the tower wil go off at random intervals, somtimes up to 76 times per 24 hours.

Ive tried several settings, from changing my APN settings to changing Firewall and NAT settings. Ive tried locking the LTE interface to several LTE bands (1, 3, 38 and 40). I also used cell tower locking to lock the LTE interface to the specific tower using the towers EARFCN and PHY Cell ID but the symptoms dont go away. Ive enabled and disabled the LTE router firewall and also disable and enabled roaming, both on the simcard and router, but no changes. Sometimes the LTE interface will even display "denied" under registration status.

Could it be that Telkom forces my LTE to connect to a different tower based on a set time or could it be that it has something to do with my router firewall and NAT settings which makes Telkom see my setup and my devise IP's as spoofing and then blacklist my router for a set time. I just cant seem to get the tower to stay connected without all lot of downtime. Some times the downtime last several hours....

 

[DapperDanMan]

up to 76 times per 24 hours.

Sounds like a tokoloshe in the system.

Either that or a hyperactive child flicking some switches on and off.

Or perhaps the distance to the tower is the aggravating factor?

 

[Kloofvreter]

My guess is distance

 

[Swingblade]

What Mikrotik router are you using? Can you post signal strenghts?

 

[Yuu]

@heinjhgrobler Welcome to the forum.

What happens if you pop the sim into a phone? Please bare in mind that there has been continuous loadshedding experienced in the country. If it's your side aswell then it could be a factor into issues.

Try the phone and let us know as much technical details as possible to help.

What sort of speeds are you getting?

 

[heinjhgrobler]

Hi all. If I put the SIM in a phone I only get a 3G signal. I make use of a MikroTik R11E-LTE model RBLHGR. With the directional antenna, I am able to get a good signal but it seems like Telkom switches the tower on and off or there must be some load balancing thing going on or a faulty component or setting on my side causing them to blacklist my LTE device for a set amount of time.

I just don't understand why it would work for several minutes or even hours and then just disappear. The tower will then not even show up on the LTE interface's Cell Monitor. It will pick up and display the same EARFCN than the tower I used was running from, but will only display other PHY Cell ID's connected to that EARFCN. The tower will disappear for minutes, sometimes hours, or even a whole day. I understand that load-shedding could be part of it but this happens 20, 30, or 40 times a day that the LTE disconnects. And sometimes it would just say "access denied" under registration status. Please see screenshots of signal strength and modem details.
RSRP -92dBm, SINR 13 dB, RSRQ -10dB on LTE band 40, 20Mhz.

 

[netstrider]

I noticed when I was on Telkom LTE (1TB) deal that it would default to 2300Mhz when downloading and 1800Mhz when performing an upload.

It is possible that it fails to connect properly from time-to-time if you force it to a particular band.

Have you tried with a different router perhapa?

 

[heinjhgrobler]

Hello,

Thank you for the reply. I have only the two routers as per the above setup schematic. If I connect the SIM to a cellphone or the Hauwei router I only receive a 3G signal, so I have no way to test this. I have a RAIN sim card which I've always used in the same setup as per the attached screenshots, before moving over to the Telkom SIM. Ive tested last week with the RAIN SIM card to ensure that my hardware is still in working order and it has worked with 99% uptime as it was for over two years.

Is there perhaps a way to set up MikroTik and RouterOS to use different frequencies for uploads and downloads?

I've noticed yesterday when arriving at home that when me and my daughter's cell phones connected to the WiFi, that the TV will almost immediately stop playing YouTube, and the MikroTik LTE will lose connection to the tower and start searching for a network. I've tested this several times to make sure it is a fact, and that seemed to be 100% correct at the time. Every time we disconnect our two phones from the WiFi the LTE will re-establish a connection to the tower until we connect our two phones to the WiFi again and it will lose connection to the tower again. It was the first time I saw this effect so directly.

Could it be related to Telkom noticing too many IP addresses on the LTE connection or could it be bandwith related limitations set by Telkom.

Yesterday after this I attempted to setup a NAT firewall rule on the router to Masquerade the IP's with the hope that the ISP will see my connection all coming from one IP address. I'm not even sure if this complies with Telkom's ISP regulations. The SIM I received is a Telkom Mobile SIM and it could be that the SIM is intended to be used in a single cellphone device. But I've purchased this device as an LTE solution and not a cellphone and it would make no sense to block people if they insert the SIM card in a WiFi modem at home. Not sure if this could also play a role.

Needless to say, after the NAT rule setup yesterday the LTE stayed connected even if we connected our cellphones, and I thought this could be it. But overnight we had another 5 disconnects from the tower. This morning I'm even connected to a "new tower" I haven't seen before with a new PHY Cell ID. The EARFCN is the same but with a different PHY Cell ID. I'm not sure if the PHY Cell ID is supposed to stay the same..?

Kind regards