Which DSL metric to monitor?

Hi,

It's a long time since I used to hang out on these forums, so hi to anyone who remembers me from my time working for Easynet, AOL and Claranet.

I now work for a SaaS Service Assurance and monitoring company called Highlight and one of the developments I'm working on at the moment is feature to help non-technical people in service providers and their customers have a better understanding of the health of an important xDSL connection.

The main metric we're going to graph and provide alerting on is xDSL sync rate, but I'm also interested in tracking one of the many error condition metrics you can collect from a xDSL modem. I want to graphically show trends around when a line is under stress due to noise or other conditions that might result in packet loss or a short outage. Where I believe that information becomes interesting and useful, beyond just knowing a line is unhealthy, is finding a pattern at a particular time of day, for example when a nearby industrial microwave turns on.

I'm planning on collecting the data using the SNMP ADSL-MIB (which is the same MIB used for VDSL2) At the moment my options of modem metrics are:

lossOfFraming - failure due to not receiving valid frame.
lossOfSignal - failure due to not receiving signal.
lossOfPower - failure due to loss of power. Note: the Agent may still function.
Inits - Count of the line initialization attempts since agent reset. Includes both successful and failed attempts.
ESs - Count of the number of Errored Seconds since agent reset. The errored second parameter is a count of one-second intervals containing one or more crc anomalies, or one or more los or sef defects.

Taken from - https://www.simpleweb.org/ietf/mibs/mibSynHiLite.php...

Each have their pros and cons, LOF will be a pretty busy counter, Inits far less so but a better indicator of when something has gone terminally wrong. Errored Seconds is also quite appealing as its units are time.

Does anyone have any feedback they can offer on which modem metric you look for to indicate a line has a transiant health issue please? Very interested in any ideas on this?

Best

Martin Saunders
Product Director
Highlight (SLM)

Edited by MartinS (Tue 27-Nov-18 12:36:36)

Hmmm.

It isn't encouraging that you can't post a working link . You need to space the closing ) from the URL.

Thanks, fixed...

You might want to look at Dslstats. Mentioned on Kitz.

A big problem with broadband connections can be contention on the back haul link especially in the evening. Ideally this should be measured somehow.

Even more worrying is failure to test it yourself before releasing it. 1st rule of software development!

Thanks Michael, I'll take a look at DSLstats. We have methods of monitoring throughput currently with our performance tests, it was specifically the physical layer of DSL we were interested in.

You won't be surprised to hear it's not the product manager that writes the code...

Most modems don't display these stats.
I'm not aware of any ISP issued modem that shows LOS/ES etc.
Different xDSL chipset manufacturers show this info differently so not easy to graph universally.

As mentioned before DslStats will graph all you want and a whole lot more but only with Broadcom based modems.
It runs on Windows, Linux or on RPi's.

Edited by j0hn83 (Thu 29-Nov-18 15:46:30)

All of these stats are available via the SNMP ADSL-LINE-MIB on many business grade routers including Cisco which is >90% of our service providers base. Any thoughts on which metric is most interesting?

In reply to a post by MartinS:

All of these stats are available via the SNMP ADSL-LINE-MIB on many business grade routers including Cisco which is >90% of our service providers base. Any thoughts on which metric is most interesting?

And there appear to be quite a number of products already providing the kind of monitoring you are hoping to achieve.

DSLstats is a cool bit of software, but you couldn't use it on an estate of tens of thousands of business broadband connections.

In reply to a post by j0hn83:

I'm not aware of any ISP issued modem that shows LOS/ES etc.

EE's Brightboxes do! In fact far better diagnostics than their latest badge-engineered BT SH 6B.