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Slow Speeds with an ISR that has AT&T LTE 4G module .5mb up and down(Smartphone gets 30mb up and down) curious as to why?

Nikkormat42
Level 1
Level 1

I have a site that must be stood up as LTE since the primary means of connectivity has been delayed.  I figured I could just use an ISR 4321 with a AT&T NIM-4G-LTE-NA cellular module since that carriers reception is excellent in this area.  I've had good results for the most part with speeds of at least 5-25mb using LTE as a secondary backup connection across the state.  Any areas that had poor speeds had bad signal strength.  After spending several days trying different antennas,  antenna placements, and opening a tac case and updating the modem firmware the best speeds I could achieve consistently via LTE were around half a meg up/down.  I'm just wondering if there is anything else someone could suggest to increase performance.  A speed of 5mb up and down would be sufficient the permanent solution is in place.

 

I have this antenna placed near a window.

LTE-ANTM-I-2-W= (LTE 2 IN 1 INDOOR WHITE ANTENNA 700MHZ-2600MHZ BAND)

 

Cell signal is good.

 

WAN-ISR#sh cellular 0/2/0 radio
Radio power mode = online
LTE Rx Channel Number = 900
LTE Tx Channel Number = 18900
LTE Band = 2
LTE Bandwidth = 10 MHz
Current RSSI = -47 dBm
Current RSRP = -77 dBm
Current RSRQ = -9 dB
Current SNR = 17.6 dB
Physical Cell Id = 97
Number of nearby cells = 1
Idx PCI (Physical Cell Id)
--------------------------------
1 97
Radio Access Technology(RAT) Preference = GWL
Radio Access Technology(RAT) Selected = LTE

 

Per Cisco Antenna Guide for ISR and CGR

 

- RSSI: Received Signal Strength Indication – a generic radio receiver technology metric for signal strength. Measures both usable signal and noise. Rated in dBm o “Good” value is greater than -80 dBm (e.g. -79 is greater than -80)

- RSRP: Received Signal Reference Power – the average of the power received of all radio resource elements that carry cell-specific reference signals. Measures usable downstream signal. Rated in dBm o “Good” value is greater than – 105dBm (e.g. -104 is greater than -105)

- RSRQ: Reference Signal Received Quality – the ratio of usable signal usable + noise signal (RSRP-RSSI). Measures how close the usable signal is to usable + noise. Rated in dB. o “Good” value is greater than -12dB (e.g. -11 is greater than -12)

- SNR: Signal to Noise (Interference) Ratio – The ratio of usable signal to noise (plus interfering) signal. Measures how much of the total signal is usable by comparing usable to noise. Rated in dB o “Good” value is greater than 5 dB (e.g. 6 is better than 5)

 

Per TAC Engineer - The configuration seems ok to me, I’ll only suggest the following changes:

conf t
controller cellular 0/2/0
no lte sim data-profile 1 attach-profile 1
int celluar 0/2/0
no bandwidth 10000
end

After doing this please power cycle the modem with this commands:

conf t
service internal
end
test cellular 0/2/0 modem-power-cycle

Give it a couple minutes so it pulls an IP from the carrier and test again.

If this does not help to improve the speed, we’ll need to update the modem firmware version using the first file in the following link:

https://software.cisco.com/download/home/286288645/type/284285628/release/5.5.58.00

Please download the file named: MC7354_1102037_05.05.58.00_00_ATT_005.011_000.spk and upgrade the firmware following this guide:

https://www.cisco.com/c/en/us/td/docs/routers/access/interfaces/firmware/Firmware_Upgrade.html

 

3 Replies 3

Hello,

 

can you post the full config of the router ? I don't want to doubt or question TAC obviously, but since you are posting this here, we might as well have a look...

 

And BTW these are the signal strength readings now.

 

ISR4321#sh cellular 0/2/0 radio
Radio power mode = online
LTE Rx Channel Number = 5780
LTE Tx Channel Number = 23780
LTE Band = 17
LTE Bandwidth = 10 MHz
Current RSSI = -35 dBm
Current RSRP = -64 dBm
Current RSRQ = -12 dB
Current SNR = 17.4 dB
Physical Cell Id = 97
Number of nearby cells = 1
Idx PCI (Physical Cell Id)
--------------------------------
1 97
Radio Access Technology(RAT) Preference = GWL
Radio Access Technology(RAT) Selected = LTE

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