----- Original Message ----- From: "Gary Stainburn" <gary.stainburn@ringways.co.uk> To: "Schools List" <suse-linux-uk-schools@suse.com>; "WYLUG Help" <wylug-help@wylug.org.uk> Sent: Friday, April 20, 2001 4:12 PM Subject: [suse-linux-uk-schools] Multi-site ADSL setup - comments wanted
It does not do NAT/masq as each PC as a public IP address. They only have a limited number of IP, so each site has a finite network size.
This setup works quite well, but the phone bills are quite extortionate. I have looked at conventional kilostream connection, but the cost of this is comparable with the current phone bills.
**** Do they qualify for 'schools internet caller' charge rate? If not - I thought BT allowed similar charging structure for any user - along the lines of a fixed charge for no metered charges either: off peak only, or including day times. Surely they don't pay for every call.......that would be horrendous.....
I have therefore had a look at ADSL, as BT's Openworld is available to most of the sites. The Openworld 500 Business is only £150 install + £70/qtr and appears as a 4 port eithernet hub. It gives 512K downstream and 256k upstream.
Don't forget that this would be shared with 20 other business users......so the throughput could be 4 times slower than a dual ISDN...but perhaps they are using a single channel - so worst case is only half the speed they are used to now....and they should get better - at least intermittently.....
On the end of this I would then put a Linux box with squid, Masq, ipchains, etc., and hang the network off the back of it.
Why not leave it as it is..... they have a cache now!
The only problem I can see is that the ADSL connection is dynamic IP, which means that the site could possibly move without warning. This will of course stuff any inbound traffic such as email.
The ADSL things I've seen provide either 1 true IP, 5 true IP or 13 true IP addresses.....or a NAT solution - which would probably be OK provided you went round and reconfigured all IP addresses (perhaps they have a DNS in that gateway box...). I assume they have more than 13 stations?
To get round this, I thought about co-hosting a box somewhere and use that as the mail gateway.
Mail feeds usually cost extra to host MX routing and and Domain name hosting is also extra sometimes.....I'm not sure about OPEN world which seemed (as with most things BT) to be more expensive than alternatives from freeserve....easynet...etc
After all that waffle, I have only a few simple questions.
1) Has anyone had experience with BT openworld? does the service perform as quoted? Is the Dynamic IP *really* dynamic, or are they just saying that?
2) Can anyone see any gaping holes in this setup?
Openworld limit IP access in someway (perhaps only by having dynamic IP....which in any case stays the same if you use it regularly so I heared...). They try to prevent web hosting and the like....
3) Assuming that dynamic means dynamic, does anyone have suggestions on how I can deliver the mail. Ideally, I would like to push the mail using standard smtp if possible rather than using fetchmail etc.