Re: Cellular backup connections

[Brandon Martin <lists.nanog () monmotha net>]

On 12/28/18 7:06 AM, Dovid Bender wrote:
> Hi All,
>
> I finally got around to setting up a cellular backup device in our new 
> POP. I am currently testing with T-Mobile where the cell signal strength 
> is at 80%. The connection is 4G. When SSH'ing in remotely the connection 
> seems rather slow. Ping times seem to be all over the place (for 
> instance now I am seeing: rtt min/avg/max/mdev = 
> 174.142/336.792/555.574/99.599 ms) . Is that just cellular or is that 
> more related to the provider and the location where I am? I could in 
> theory test with VZ and ATT as well. With Verizon they charge $500.00 
> just to get a public IP and I want to avoid that if possible.
>
> Thanks and sorry in advance if this is off topic.

LTE with a good connection on a lightly loaded cell should be 
significantly less than that in both absolute terms as well as jitter.

I used LTE (Sprint) for a couple years as my primary connectivity when I 
moved out into an area with zero connectivity (fixing that now).  I 
typically saw ~30-40ms to Chicago, which is the nearest major carrier 
PoP.  Jitter was typically less than 10ms.  VoIP was usable.  Others in 
the area on other carriers have reported similar.

Sprint gave me a public IP with no up front charges but did charge $5/mo 
for it.

As you're probably aware, the "signal strength" ("bars") indicators that 
are presented to the consumer-facing interfaces are often very cooked. 
Depending on which RSSI you're looking at, a "very good" signal is 
probably in the realm of -70dBm to -110dBm (note that there are two RSSI 
metrics commonly used with LTE, and they tend to differ by ~20dB).

--
Brandon Martin