Can I use * for 4 Magicjack lines used by 30 analog phones?

Can I use 4 Magicjack lines for 33 analog lines. What kind of hardware do I need for it if I install
Linux followed by * on a older Pentium 4 computer?

Do you mean 30 phones using the 4 MagicJack lines for calling? Yes, you can do that with Asterisk. To do it all via PCI cards will be spendy. To get 4 lines + 30 phones using Digum’s PCI cards you’ll need:

1 TDM2400 card configured with 6 quad FXS modules. MSRP about $1700
1 TDM2400 card configured with 1 quad FXO module and 2 quad FXS modules. MSRP $1000.

$2700 in cards.

If that’s in your budget, then you’re set.

Otherwise, the low-budget way is to put a single Digium TDM410P card with 4 FXO modules (MSRP $450) into the machine and connect each of the 30 phones to an IP analogue terminal adapter such as the Grandstream HT 486 or the Linksys PAP2. You can get those for $30-40 a piece or less.

If I understand correctly, MagicJack is an ATA bundled with an ITSP service. If you were using Asterisk to concentrate the calls, it would seem more sensible to me to connect Asterisk directly as VoIP to an ITSP, rather than outputting analogue and then immediately converting to VoIP.

Technically, connecting asterisk direct to magicjack’s servers via sip is against their Terms Of Service. So while you can do it, you run the risk of getting your account(s) terminated. And from my understanding, they’re pretty draconian about “kill accounts, ask questions later”.

The reference I found didn’t actually say they used SIP, although it would have been a good guess.

I was thinking more in terms of going with an ITSP that didn’t try to bundle the ATA.

If they are hot on T&Cs, do they actually allow you to concentrate traffic?

One extra detail: any solution that involves two D to A conversions will not work with 56k modems. This would include most “analogue” PABXes, these days.