Reading Link Distance using SNMP OID for PMP100 v10.4


How does one get the link distance using SNMP (and the OID) for a Canopy SM on firmwares v10.4 or above?  I see from the GUI that it has the Link Distance under the Field tab called "Air Delay".  However, the SNMP value being returned for the Air Delay OID is not in actual feet nor miles.  It's just some integer number.  Like everything we see that is under 5miles or so just has like 2-3 digit numbers.  Whereas the GUI represents and shows this value along with the distance in readable form like 5 miles (5086 feet).



Air delay is the field that displays the distance in feet between this SM and the AP on the GUI. To derive the distance in meters,multiply the value of this parameter by 0.3048.

OID for the same is . and it will give the value of the air delay in the form of bits.Please find the attached image to verify the same.

To determine the actual distance,you need to convert that binary or bit obtained from the OID of Air delay value in the decimal form.


Hi Kimmi;

Thanks very much for that info.  Before seeing your reply (as I had forgotten to subscribe for any responses to be emailed to me), I had actually started to do my calculations.

So, using Mikrotik Dude monitoring, I created a function with the following:-

"concatenate(string_substring(((oid("")*147.4453125)/5280),0,5)," mi")"

Essentially, I took the SNMP AirDelay value * by 147.4453125 = feet.  Then, to convert feet to miles is where we have the full formula, i.e. (AirDelay *147.4453125)/5280 = miles.  

So, hopefully this helps someone else seeking information on it.   So far, it has reported all the correct mileage for all of our PMP100 SMs still in the field.

If I had seen your reply post with the metric equivalent first, this may have saved some basic math scratch your head on how to work this out.   I will certainly save your muliplier factor / parameter.

Thank you so much.