[Asterisk-Users] HT286, fax and FXS impedance for Europe?

[Philipp von Klitzing]

Hi there,

the latest firmware (at least 1.5.0.0) for the Grandstream HT286 
HandyTone now has an option to set the FXS impedance. It appears that for 
EU countries the "CTR21" is the correct setting. 

My question: Does changing this setting improve fax operation for you?

Cheers, Philipp


Source:
http://www.cmlmicro.com/Products/Reports/DE8681%20CTR21%20Compliance.pdf

"In 1998, many European telecom standards were replaced with a single 
harmonized standard CTR21, which applied to all EU member countries. 
Compliance with CTR 21 was mandatory for CE marking. On 8th April 2000 
however, a new directive, 1999/5/EC, commonly known by its short name 
Radio and Telecommunication Terminal Equipment (RTTE), established a new 
regulatory framework for telecom approvals, the RTTE Directive repealed 
CTR21 and declared that it no longer be mandatory for devices that 
connect to public network phone lines.  

Under the RTTE directive, the only mandatory requirements for CE marking 
of a typical modem are those for safety and EMC. Otherwise, products are 
presumed to comply with the Directive when they meet the requirements 
within the usage conditions for which they are intended. While many EU 
countries now maintain certain recommended requirements for interfacing 
to their phone lines, compliance with these requirements is not mandatory 
for CE marking. To deal with the uncertainty regarding telecom 
compliance, some manufacturers have continued to design for compliance 
with CTR 21. This is perfectly acceptable, but it is  
no longer mandatory."