I'm changing phone providers soon and the new provider is going to connect a new copper pair to the house. Both lines are going to be active for a time and I may switch back to my current provider in future, so I'd like to put a DPDT switch in before the master socket to easily switch between the two lines, but would this affect my adsl / vdsl sync speeds at all?

I'm planning on using gel crimp connectors for connecting the wires together and getting a DPDT switch with screw connectors.

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    \$\begingroup\$ If this is residential, you should just be able to switch connections at the demarc which should have rj11 at this point. \$\endgroup\$ – Passerby Sep 12 '16 at 16:28
  • \$\begingroup\$ We've got extensions and an alarm system wired into master socket, so was looking for someway to swap connections before this point to save having to move multiple connections each time \$\endgroup\$ – Matt Sep 13 '16 at 12:30

Any impedance "bumps" in the circuit will have "some" affect on achievable data rate, but as long as a switch is a sensible one and the connections are competent and the pairs are kept as undisturbed as possible, I'd expect no significant impact.

Keep twisted pairs twisted for as much of their length as is sensibly possible - no need to overdo it. ie Avoid having wires form a large loop or the pair broken up so wires go via different routes.

I dislike crimp connectors of any sort for long term use. They may very well work indefinitely, but I try to solder connections where possible - with memories of bad experiences long ago. YMMV :-).


While these days it does not make as much difference most telcos frown on users making strange hookups.

That said, having the two jacks adjacent and a flylead to select would be the simplest. If you want to have switch it should work, the polarity of the line voltage may be opposite (and unpredictable) and residual charge in device capacitors may cause an appreciable 80V spike on fast switch-over.

As there is no need to rush the switch is not needed and the most likely failure point, the link negotiation after switching is going to take time anyway.

For faster switch over and/or network speed you could use two modems and try find some load balancing software.



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