which phone sockets need Filters

[downwithsky]

My wifi keeps dropping and no dialling tone on landline.  Have had this system since 2013 and all has been fine until recently.  Could anyone tell me which phone sockets need a filter 

[TimmyBGood]

@downwithsky 

If you don't have a master socket with a filtered faceplate, then it and any other socket which has a phone or similar device in use should have a microfilter.

However, any fault is more likely to be external to your property.

[downwithsky]

Thank you, its just my main phone socket has another sky socket with 2 sockets in and I just wondered whether that is a built in filter.  Everything has been working fine until now though