Author: Roger Hardiman

Ethernet over Mains test

I tested some Ethernet over Mains adapters at Parkend today and used the TP Link PA-411 adapters which follow the Homeplug AV500 standard.
There are 3 buildings on site (Station, Goods Shed and Signal Box) and the site is 3 phase (each building is on a different mains phase) but the Neutral wire that Homeplug uses is common to all 3 phases so this was not a problem.

Testing was carried out by accessing the web based service from a laptop.

When connected the laptop directly to the broadband my laptop had the full 80Mbps download and 20Mbps upload. (The FTTC broadband cabinet is less than 100 metres)

From the Goods Shed (where the telephone exchange is) I got a download speed of 25 Mbps.
From the Signal Box I got a download speed of 37 Mbps.

The adapters deliver a good throughput over the 3 phase mains to allow internet access and VoIP data.

Manufacturer refurbished PA-411’s are £11 on eBay at the current time so are very cheap.



Netgear DGN2200v4 Disable SIP ALG to make ringing stop

I had to disable SIP ALG on my Netgear DGN2200v4 ADSL Router to fix a SIP problem.

In my office I have a Grandstream HT802 ATA. This is a 2 port (2xFSX) ATA.
It connects to the internet via a Netgear DGN2200v4 ADSL router. Elsewhere across the internet is our Asterisk server, also behind a NAT broadband router.

Both FSX ports have SIP accounts linked to the Asterisk box and I had a phone on each FSX port. I’ll call these extension 401 and extension 402.

If ext 401 calls ext 402 then extension 402 will start ringing. (OK so far),
My problem was that if 401 then hung up the call before 402 answered, 402 would keep ringing and ringing so something was going wrong.

If I did this test the other way around then everything was fine.
i.e. Ext 402 calls Ext 401 and 401 starts to ring. If I then hangup on ext 402 the call clears down properly and ext 401 stops ringing.

The fix turned out to be disabling the SIP ALG support in the Netgear DGN2200 v4.
It is found in Advanced -> Settings -> WAN Setup


Grandstream HT802 ATA – Pulse Dialling and Hook Flash

I’ve been looking at the Grandstream HT800 series ATAs to allow analogue telephones to connect to the asterisk server. Based on cost ‘per FSX port’ we settled on the HT802 which is a 2 port ATA (2xFSX ports). They are about £35 (so £17.50 per port) and a couple were ordered.

The HT802 is a fairly new ATA which is still being manufactured and still receives firmware updates and has technical support.



Pulse Dialling (Loop Disconnect Dialling)
Firmware for the HT802 adds “Enable Pause Dialing:” to the web config page. We have tested it with an old BT phone with the ‘rotary dial’ and some newer phones that support DTMF and Pulse Dial (Loop Disconnect Dial) with a MF/LD switch. It all worked well and we can make calls from all the old analogue phones we tried to the asterisk extensions.
Pulse Dialling needs to be enabled on each FSX port in the web config page

Hook Flash
Also in the web config menu is “Enable Hook Flash:”
Then it is enabled you can flash the hook (press the hook button down and let it go quickly, putting your first call on hold and allowing you to make a 2nd call. This is handy as it allows you to use call holding and do call transfers. But in practice users just end up having two active calls without realising.
Hook Flash can be disabled on each FSX port in the web config page.

Other Settings
There are settings for SLIC (which we set to UK) and settings for “Enable High Power Ring” which we have not tested yet but may help with long lines.