Re: Estimated LTE Data Utilization in Failover Scenario

[Blake Hudson <blake () ispn net>]

Matt Harris wrote on 7/31/2019 9:46 AM:
> On Wed, Jul 31, 2019 at 9:21 AM Shaun Dombrosky 
> <SDombrosky () blackfoot com <mailto:SDombrosky () blackfoot com>> wrote:
>
>     Good Morning,
>
>     First time NANOG poster, apologies if I breach etiquette.
>
>     Does anyone have any first-hand data on how much data a
>     small-medium business (SMB) can expect to consume in a failover
>     scenario over a 4G/LTE connection?  Retail, under 50 head count,
>     using PoS, maybe cloud accounting software, general internet
>     activity, 8 hour time period.  Wonder if anyone is using a
>     Cradlepoint or SD-WAN solution that could pull a few quick numbers
>     from a dashboard for me.  I haven’t had much luck in my searches.
>
>     Appreciate any info anyone can provide.
>
>     Thanks,
>
>
> Hey Shaun,
> I'd recommend pulling that data from the device normally facing their 
> internet connection. Does it support netflow or even just basic snmp 
> statistics that you could graph? Ostensibly the traffic level would be 
> the same regardless of whether using an LTE backup connection or the 
> primary internet connection unless you somehow prohibited certain 
> traffic when on LTE. Ultimately though, your best bet is going to be 
> to get real stats over the course of a couple of weeks and then you'll 
> understand better the traffic patterns based on time of day, day of 
> the week, etc, as well, as this is likely relevant.
>
> Good luck!
100% agree with Matt. Something also to keep in mind is the SMB's peak 
data rates. The primary (I assume ethernet) uplink may have a sub 10ms 
latency and 100Mbps or greater data rate while the LTE connection is 
probably several times slower in terms of bandwidth and latency. If 
designing a failover connection, customer expectations may need to be 
managed: internet access may be up, but will be noticeably degraded when 
on LTE. A backup cable connection may be better for VoIP or other 
latency/jitter sensitive applications and of course anything that relies 
on a static IP (server, vpn, etc) will probably break if the primary 
connection is down. Would be a good idea to test the failover connection 
during a few different time periods to gauge employee experience.

--Blake