Re: [SLUG] Brain Freeze - ADSL
On 12/12/06, Oliver Hookins [EMAIL PROTECTED] wrote: Not quite right, you still have layer 2 frames which are disassembled and reassembled. However your device is operating as a simple ethernet (or ATM if your ISP supports it) bridge rather than also encapsulating the traffic in PPP which is the norm, hence less overheads. IIRC (and I'm sure someone will correct me if I don't), the famous 1492-byte MTU on DSL connections is caused by the 8 bytes of PPPoE headers taking up part of the 1500-byte ethernet frame. Switching to L2 removes that overhead, which has a few benefits: avoids mysterious MTU issues, means that 1500-byte packets on the ethernet segment don't have to be re-packaged as 1492-byte packets to go over the DSL segment (I think this is what O was talking about), etc. /me sits back and awaits flameage -- There is nothing more worthy of contempt than a man who quotes himself - Zhasper, 2004 -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
Re: [SLUG] Brain Freeze - ADSL
On 12/12/2006, at 8:12 PM, Zhasper wrote: On 12/12/06, Oliver Hookins [EMAIL PROTECTED] wrote: Not quite right, you still have layer 2 frames which are disassembled and reassembled. However your device is operating as a simple ethernet (or ATM if your ISP supports it) bridge rather than also encapsulating the traffic in PPP which is the norm, hence less overheads. IIRC (and I'm sure someone will correct me if I don't), the famous 1492-byte MTU on DSL connections is caused by the 8 bytes of PPPoE headers taking up part of the 1500-byte ethernet frame. Switching to L2 removes that overhead, which has a few benefits: avoids mysterious MTU issues, means that 1500-byte packets on the ethernet segment don't have to be re-packaged as 1492-byte packets to go over the DSL segment (I think this is what O was talking about), etc. /me sits back and awaits flameage I personally use PPPoA from my Cisco and this solves the PPPoE MTU problem too :) -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
[SLUG] Re: Brain Freeze - ADSL
Zhasper wrote: On 12/12/06, Oliver Hookins [EMAIL PROTECTED] wrote: Not quite right, you still have layer 2 frames which are disassembled and reassembled. However your device is operating as a simple ethernet (or ATM if your ISP supports it) bridge rather than also encapsulating the traffic in PPP which is the norm, hence less overheads. IIRC (and I'm sure someone will correct me if I don't), the famous 1492-byte MTU on DSL connections is caused by the 8 bytes of PPPoE headers taking up part of the 1500-byte ethernet frame. Switching to L2 removes that overhead, which has a few benefits: avoids mysterious MTU issues, means that 1500-byte packets on the ethernet segment don't have to be re-packaged as 1492-byte packets to go over the DSL segment (I think this is what O was talking about), etc. There's more to it that that. If it's telstra DSL, there's also L2TP overhead - that's the tunnel that takes a load of aggregated PPP sessions and dumps them onto your ISPs ppp termination box. The actual telstra-recommended MTU that ISPs generally force is more like 1452. BB -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
Re: [SLUG] Brain Freeze - ADSL
Oliver Hookins wrote: O Plameras wrote: Voytek Eymont wrote: On Mon, December 11, 2006 11:21 am, Scott Waller (Lots of Watts) wrote: Finally changed over to Layer2 1.5 meg blah blah blah. And am having problems with my setup. Scott, dumb question: I thought about this. what's the advantage of having a 'Layer2' connection over the usual 'userid/password/login' connection ? Better throughput than Layer3, in general. Devices on Layer2 work less as hard than devices on Layer3. Layer3 assembles data before send and dis-assembles at receive. Layer2 does not. So, less latency. Not quite right, you still have layer 2 frames which are disassembled and reassembled. However your device is operating as a simple ethernet (or ATM if your ISP supports it) bridge rather than also encapsulating the traffic in PPP which is the norm, hence less overheads. A somewhat detailed description. 1. Layer 2 networks are connected together using hubs, bridges and switches. Common denominator is that these devices only forward frames. None of these devices have to disassemble or reassemble data. Specifically, 1.1 Hubs take each frame that is received and send duplicate frames simultaneously out to all other ports. 1.2 Bridges forward broadcasts between two connected networks until they have located all hosts. 1.3 Switches forward broadcast traffic only when it doesn't know where a host is. 1.4 Because nothing is done to the data along the way, layer 2 networks are often considered to be 'faster' than a layer 3 network. 2. Layer 3 networks are built to run on top of layer 2 networks. 2.1 In an IP layer 3 network, the IP portion of the datagram has to be read. 2.2 This requires stripping off the datalink layer frame information. 2.3 Once the protocol frame information is stripped, the IP datagram has to be reassembled. 2.4 Once the IP datagram is reassembled, the hop count has to be decremented, the header checksum has to be recalculated, a lookup for routing must be made, and only then can the IP datagram be chopped back up and inserted into frames and transmitted to the next hop. All of this takes extra time. O Plameras -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
Re: [SLUG] ADSL without paying for a phone line?
If it exists in your area, the best you can hope for is cable. This is pretty fast down, pretty slow up. But if you aren't running a home webserver or doing a lot of bittorrenting, it should be just fine. At least _I_ think it's just fine... compared to the 100Mb-ethernet-to-the-bedroom I had at university (the perk of being the network sysadmin at the college) all this stuff is slow anyway. Personally I don't find the difference between cable and ADSL very large, and the cable is MUCH MUCH MUCH more reliable. As in I've only ever heard of one person that has ever had trouble reliable. And I can get 1Mb a second to my server in the US, so that's everything I need ok :) Adam K Sonia Hamilton wrote: (slightly OT...) Is there a way of getting ADSL at home without paying for a landline? I use my mobile for everything, and don't use the landline but am paying for it to run ADSL on. I know there's things like wireless from http://www.unwired.com.au/, but to get decent downloads the costs would work out the same. -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
[SLUG] ISP in Sydney??
My wife and I are quite possibly moving to Sydney - maybe to Manly - in a couple of months. I go to school online and need a high speed connection, preferrably one with a static IP address, any recommendations for which ISP is 'best'? Thanks. PS coming from New York and I'm the only Yank in the family. -- Nathan D.Eckenrode www.EckenrodeHouse.net [EMAIL PROTECTED] 646.942.7669 pgpEYhalRsHDa.pgp Description: PGP signature -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
Re: [SLUG] ISP in Sydney??
Nathan Eckenrode wrote: My wife and I are quite possibly moving to Sydney - maybe to Manly - in a couple of months. I go to school online and need a high speed connection, preferrably one with a static IP address, any recommendations for which ISP is 'best'? Hi Nathan, You should probablt get ADSL, but don't expect it to be as cheap or as fast as what you get in the US :-). Best advice is to avoid the big ISPs like Telstra (Bigpond) and Optus because they are usually pretty clueless. The best bet would be to look here in the broadband choice : http://bc.whirlpool.net.au/ and chose an ISP that way. Erik -- +---+ Erik de Castro Lopo +---+ We can build a better product than Linux -- Microsoft Corp.'s Windows operating-system chief, Jim Allchin. One has to wonder why, with their huge resources, they haven't. -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
Re: [SLUG] ISP in Sydney??
On 12/13/06, Nathan Eckenrode [EMAIL PROTECTED] wrote: My wife and I are quite possibly moving to Sydney - maybe to Manly - in a couple of months. I go to school online and need a high speed connection, preferrably one with a static IP address, any recommendations for which ISP is 'best'? Nathan. Until you actually get here and decide where you're living, it's really difficult to say. What I can say is for you to NOT expect the broadband offerings in Australia to be either as cheap or as fast as the mainstream cities in the US have available. Currently, you can get ADSL 1 almost everywhere in Sydney - with Telstra's recent decision to uncap the artificial ADSL download speeds they have previously imposed, you can get up to 8 meg download. If you're fortunate enough to live somewhere close to an exchange which has ADSL2+, you can get up to 20 meg download speed through Telstra, 22 meg through some of the alternate providers. It's probably already been pointed out, but you should look at the following web site http://bc.whirlpool.net.au Once you've got your place and phone installed, you can check out the options there and find the best plan. Depending on how financially conscious you are, I'd suggest *not* using Telstra except as a last resort - they are the most expensive option available. DaZZa -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
[SLUG] Gnome WeatherApplet
Hi, Is there a reason why I cannot get the BoM radar map to show in the Gnome WeatherApplet after I input the url into :preferences:general:? John -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
Re: [SLUG] ISP in Sydney??
Erik de Castro Lopo wrote: You should probablt get ADSL, but don't expect it to be as cheap or as fast as what you get in the US :-). When shopping for ISP's you would often encounter the word quota, a word that I believe is non-existent in American ISP's. =P Best advice is to avoid the big ISPs like Telstra (Bigpond) and Optus because they are usually pretty clueless. I have had consistent download speeds with Internode. In 90% of the time I get to utilise my 1.5Mbps connection. 150k/sec steady downloads on most sites including non-Aussie ones. Hope that helps, Carlo The best bet would be to look here in the broadband choice : http://bc.whirlpool.net.au/ and chose an ISP that way. Erik -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
Re: [SLUG] Gnome WeatherApplet
On Wed, Dec 13, 2006 at 10:03:40 +1100, John wrote: Is there a reason why I cannot get the BoM radar map to show in the Gnome WeatherApplet after I input the url into :preferences:general:? It works for me. The URL I'm using is: http://mirror.bom.gov.au/radar/IDR033.gif (for Sydney). Cheers, John -- Minis on the other hand are just the wrong size. Too small to work on directly and too large to put upside down on the workbench. -- Craig 'Stevo' Stephenson -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
Re: [SLUG] ISP in Sydney??
This one time, at band camp, Carlo Sogono wrote: When shopping for ISP's you would often encounter the word quota, a word that I believe is non-existent in American ISP's. =P You'll also encounter the word unlimited, which is never the case. Similarly when looking at mobile and home phones, you'll get the concept of a cap, which is nothing like what you expect from the term. Oh and when you order your phone line, make sure you get the rep to put ADSL Required on the order, or you might not be able to get it. -- Rev Simon Rumble [EMAIL PROTECTED] www.rumble.net If I were on life-support, I'd rather have it run by a Gameboy than a Windows box. - Cliff Wells in comp.lang.python -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
Re: [SLUG] Gnome WeatherApplet
Thanks John. It helps if you use the right url :-) J On 12/13/06, John Clarke [EMAIL PROTECTED] wrote: On Wed, Dec 13, 2006 at 10:03:40 +1100, John wrote: Is there a reason why I cannot get the BoM radar map to show in the Gnome WeatherApplet after I input the url into :preferences:general:? It works for me. The URL I'm using is: http://mirror.bom.gov.au/radar/IDR033.gif (for Sydney). Cheers, John -- Minis on the other hand are just the wrong size. Too small to work on directly and too large to put upside down on the workbench. -- Craig 'Stevo' Stephenson -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
Re: [SLUG] Determining PCI version
This one time, at band camp, Howard Lowndes wrote: I need to be able to determine whether a mobo I have can handle PCI v2.2 What is the best way of doing this? Indeed, I'm having a similar problem in that my server's mobo is very finicky about the PCI cards it accepts. My approach so far, though I haven't got anything definitive right now, is to look up the chips for the PCI bridge reported by lspci. This might help you. -- Rev Simon Rumble [EMAIL PROTECTED] www.rumble.net Bore, n. A person who talks when you wish him to listen. - Ambrose Bierce: The Devil's Dictionary -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
Re: [SLUG] Determining PCI version
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 Howard Lowndes wrote: I need to be able to determine whether a mobo I have can handle PCI v2.2 What is the best way of doing this? dmidecode may give you some extra info. I'm looking now, it doesn't specifically state the PCI version, but it reports other info which may help. - -- dave. -BEGIN PGP SIGNATURE- Version: GnuPG v1.4.2.2 (GNU/Linux) iD8DBQFFf00MhPPdWeHRgaoRAoAVAJ9X+bovJ4wNcItyIjHzQsh/XJjLDgCfZQfa l2wIQ5gBJmMI1QR4LG0qfWQ= =TLiW -END PGP SIGNATURE- -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
