[asterisk-users] SIP vs Analog lines

[Chris Bagnall]

In the last couple of years I can only think of two sites where we've installed E1 connections, compared to many tens of sites where we've gone with VoIP only.

You can mitigate against QoS issues by simply installing two DSL connections (one for internet, one for voice). With a decent load balancing router (pfSense works well) this also gives your users failover - if one DSL fails, both internet and voice continue to function. Sure, call quality might suffer and internet speed may drop off a little, but both will continue to work.

In fact, one of our sites (a large international company just outside Coventry) has two E1s and a number of IP connections (both fibre and ADSL), and the IP links have been noticeably more reliable than the BT-provided E1s.

I don't know what the story is with reliable IP links in other countries, but I agree with Gordon's comments in relation to the UK:

> Here in the UK we have a generally excellent wholesale (ADSL) broadband
> system, let-down at times by the back-end ISPs who buy into it, so picking
> a good back-end ISP is worth it.

There's a significant advantage to be gained by peering directly with your suppliers. For example, we peer with our ADSL wholesalers, as well as with our upstream providers (both for incoming and outbound calls). This prevents most calls from going over an IP link where we (by which I mean us and our suppliers, collectively) do not have end-to-end control.

Regards,

Chris