lunedì 12 novembre 2012
Un modem (modulatore-demodulatore) è un dispositivo che trasforma i dati digitali di una macchina modulando segnali elettrci che possono essere trasportati lungo un canale telefonico, e viceversa può decodificare, cioè demodulare i segnali telefonici entranti in dati digitali.
Tipicamente un modem è dotato di un collegamento alla linea telefonica via una cavo RJ-11, ed alla rete internet via un connettore RJ-45, se non è direttamente incorporato in un altro dispositivo.
Cavo di collegamento con connettori RJ-11 e RJ-45:
Le classi pricipali di modem sono i modemi analogici o dial-up, che sfruttano tradizionalemnte la banda vocale del canale telefonico, e causa le connesse limitazioni di frequenza sono chiamati anche modem a banda stretta. Oggigiorno sono rappresentati essenzialmente dai modem interni o modem esterni con funzione di fax.
Esempio di modem interno 56Kbit/s:
Modem esterno analogico con funzione di Fax:
I principali standard a banda stretta e le relative velocità massime di traferimento dati sono:
Invece i modem broadband, cioè a banda larga, sono modem che usano frequenze più alte di quelle per la trasmissione della voce nel canale telefonico. La tecnologia usata è quella DSL (Digital subscriber line), che si è evoluta nell'ADSL e nella sue varianti. I modem ADSL sono generalmente dispositivi esterni, la tecnologia necessaria è difficilmente compattabile in schede interne.
Modem ADSL2+ con velocità fino a 24 Mbps:
Nella tecnologia ADSL (Asymmetric Digital Subscriber Line), o DSL asimmetrica, la velocità di trasferimento dati dalla rete telefonica verso il client locale (downstream o download) è nettamente superiore du quella di upload dal client verso la rete telefonica (upstream).
I principali standard ADSL e le relative velocità downstream sono:
Modem a banda larga con velocità fino a 100 Mbps:
Un filtro ADSL è un filtro passa-basso analogico installato tra il telefono analogico e la presa della linea telefonica, al fine di evitare interferenze reciproche con la linea DSL (Digital Subscriber) operante sulla stessa linea.
In Italia si usa tipicamente un filtro tripolare, che è uno spinotto per le prese tripolari che presenta due uscite: una per i terminali analogici e l'altra per il modem ADSL.
Inviato da: Deanna Williams il: 2018-09-05 13:00:37.152452
Inviato da: MelodyWilson il: 2018-09-14 14:52:12.903369 Key decisions Protects against noxious sites and records: upheld Kaspersky activation code science lab triumph advances, Kaspersky Free antivirus gives amazingly dependable assurance against suspicious or pernicious documents and projects, and cautions you to without a doubt vindictive sites - along these lines you'll surf inside the net securely. Safeguards against phishing assaults: By simply visiting a site or hole Associate in Nursing email you'll turn into a casualty of a phishing assault that endeavors to take your money or character. Fortunate that Kaspersky 6.0 has created to refresh consequently. You can alter time Kaspersky total security checking, so you don't have to hold up prolonged stretch of time before PC.
Inviato da: Kaspersky activation il: 2019-03-12 07:52:41.159561 Are you experiencing daily problems with your QuickBooks Online Support? Here you go! Our QuickBooks Online Support team is here to help you. We are the simplest engineer in our team and They are working round the clock to overcome your expectations. We are happy to serve you better, If any user wants quick solutions regarding QuickBooks Online Support Number, then our QuickBooks Online Support Phone Number +1-844-551-9757 is the easiest way to call 24/7 workdays. This is our toll-free number and provides users with a fast solution.
Inviato da: QuickBooks Online Support il: 2019-02-27 08:33:08.895884 Instagram is available for free on iOS and Android devices. Get start with instagram video downloader now.
Inviato da: instagram video downloader il: 2019-02-26 04:07:33.155145 amazing post man
Inviato da: how to make google my homepage to browse the internet? il: 2018-09-11 16:16:48.059412 The principle modem classes are simple or dial-up modalities, which generally misuse the vocal band of the phone channel, and as a result of the related recurrence, impediments are additionally called narrowband modems.
Inviato da: Bates Motel Mike Vogel Jacket il: 2018-09-05 12:59:05.027531 Popeyes is an American multinational chain of fried chicken fast food restaurant. The journey of Popeyes was started in the year 1972. In the year 1972 Popeyes was started as a small restaurant. tellpopeyes.com | www.tellpopeyes.com
Inviato da: www.tellpopeyes.com il: 2018-11-27 08:17:49.118842 I really happy found this website eventually. Really informative and inoperative, Thanks for the post and effort! Please keep sharing more such blog. Norton.com/setup – Download, install and activate Norton antivirus setup to get robust security at www.norton.com/setup. We Will help you to redeem product key. Norton.com/setup - Enter Your Product Key Here norton.com/setup norton help roadrunner email webroot antivirus
Inviato da: norton.com/setup il: 2019-03-13 16:22:39.430228 This is a very amazing game with the free robux generated by the free robux generator for the free roblox robux game to play free.
Inviato da: how to get robux for free il: 2018-09-05 13:11:18.296174 amazing post man myhr cvs login
Inviato da: myhr cvs login il: 2018-09-14 20:39:01.895575 we are providing you step by step procedure for downloading, installing and activating any McAfee antivirus security software by using a 25 character alpha-numeric activation key code. mcafee.com/activate | mcafee.com/activate
Inviato da: mcafee.com/activate il: 2018-12-27 09:48:54.144824 Thank you for any other magnificent post. The place else could anybody get that kind of information in such an ideal manner of writing? bouncing balls
Inviato da: bouncing balls il: 2018-06-15 10:22:52.259492 Wow great blog I think my friend was right, My friend suggest me to visit your blog to get useful information and now I’m also satisfied he was right now I’m your visitor. good work sir keep it up.
Inviato da: katniss everdeen jacket for sale il: 2019-02-25 12:52:51.73314 amazing post man
Inviato da: icloud login email il: 2018-09-14 19:58:57.556607 It's surprising you aren't more popular given that you definitely possess the gift. antimalware service executable windows
Inviato da: Eric Luster il: 2018-07-11 20:13:33.629098 This is really an amazing article. Your article is really good and your article has always good content with a good powerpoint with informative information. norton.com/setup mcafee.com/activate office.com/setup
Inviato da: norton.com/setup il: 2019-03-09 21:21:29.384367 Nice Post aptoide installer
Inviato da: aptoide installer il: 2018-10-23 19:06:42.568292 Great icloudlogin.wiki
Inviato da: icloudlogin.wiki il: 2018-10-23 19:52:59.382647 Thanks for sharing information https://printersupportnumbercare.com/
Inviato da: sarajacob il: 2019-03-11 17:57:45.907752 Amazing icloud login problem
Inviato da: Rachel il: 2018-09-26 18:04:53.034031 Service providers usually now hands off their own modems to support them but during my university assignments task i only uses an external modem for usage.
Inviato da: Sara Craw il: 2018-08-20 09:11:12.356928 Nice sharing amazing one keep sharing more thanks for all lovely one binary today 5
Inviato da: andrea rose il: 2019-03-01 23:18:00.651237 Www.Mcafee.Com/Activate, Www.Mcafee.Com/Retailcard - How You Can Redeem Your McAfee Product Key and Get You Antivirus Activated In Few Easy steps. Quick Learn How You Can Use mcafee.com/activate to Activate McAfee using Product Key. Mcafee.Com/Retailcard
Inviato da: Www.Mcafee.Com/Mis/Retailcard | Www.Mcafee.Com/Mtp/Retailcard il: 2018-12-25 07:30:14.360872 Norton antivirus Setup programming appeared as a match and big programming which can comprehend and void such Malware and Threats. It monitors threats around the clock and comes with a 100% guarantee. Our Norton.com/setup Services unit faithfully within your provoke respect and safety. www.norton.com/setup Norton Setup Download Free Norton Setup Enter Product Key Norton Setup Online Norton Setup Support Norton.com/nu16
Inviato da: Norton Setup il: 2019-02-26 10:04:40.006883 Quickbooks Support Number - To fix issues related to QuickBooks Desktop, Online, Enterprise, MAC, Payroll & POS, instantly dial QuickBooks Technical Help Desk Number 1-888-986-7735 and connect with Certified QuickBooks experts. Quickbooks Payroll Support Number | Quickbooks POS Support Number | Quickbooks Enterprise Support | Quickbooks Desktop Support | Quickbooks Mac Support | QuickBooks Error Support | QuickBooks Online Support
Inviato da: Quickbooks Support il: 2019-01-10 08:29:47.095339 AOI Tech Solutions is a best network security providing company in US, UK, Canada and Australia. Higher customer satisfaction and affordable services. Trained experts with lot of experience. For more details call us - 888-875-4666.
Inviato da: AOI Tech Solutions il: 2019-01-28 13:12:39.103052 Rv Homes is an energetic network that gives shared spaces and pg in gurgaon to make an all the more satisfying way of life. Home to more than 500 individuals from varying backgrounds, every one of our inhabitants share an inquisitive personality and a craving to carry on with their life in a progressively associated path with the general population around them. This aides in achieving most astounding consumer loyalty rate for Rv Homes luxury room in gurgaon.
Inviato da: luxury room in gurgaon il: 2019-03-12 19:58:41.12494 I just got to this amazing site not long ago. I was actually captured with the piece of resources you have got here. Big thumbs up for making such wonderful blog page! Stretch Marks
Inviato da: Stretch Marks il: 2018-09-05 12:52:35.775385 Norton is one of the trendiest antiviruses everywhere throughout the world. Furthermore, it is notable for ensuring the gadget and furthermore giving a one-stop security answer for every one of the clients worldwide with just one click. Sign in to norton.com/setup
Inviato da: norton.com/setup il: 2018-12-27 09:50:06.523153 Thanks for sharing this piece of information. I really enjoyed it. keep up the good work and all the very best of luck! Christian Grey Brown Jacket
Inviato da: Emma Jason il: 2018-09-25 19:13:01.884404 HP Printer Support – HP Inc. is American Multinational Information Technology Company engaged in manufacturing a wide range of hardware and software components along with allied services to the consumers and businesses. From laptops, desktops, tablets, storage devices to peripheral devices, it offers all types of tech products.
Inviato da: Hp Printer Assistant il: 2019-01-19 11:23:03.222112 amazing post man more
Inviato da: more il: 2018-09-18 18:32:32.382706 You have observed very interesting points ! ps nice website .
Inviato da: Buy Web Traffic il: 2019-02-02 16:15:20.967605 This article gives the light in which we can observe the reality. This is very nice one and gives indepth information. Thanks for this nice article. Counting Calories
Inviato da: Counting Calories il: 2018-09-05 13:02:00.611959 I like viewing web sites which comprehend the price of delivering the excellent useful resource free of charge. I truly adored reading your posting. Thank you! How To Start Running
Inviato da: How To Start Running il: 2018-09-05 12:59:52.706863 Thanks for sharing information
Inviato da: Sara Jacob il: 2019-03-11 17:56:36.735055 Quickbooks pro is easy to use and very understandable. Quickbooks pro is simply good work with our financial business. Quickbooks pro accounting software is self employed software. Quickbooks pro software application is made with a responsive and user friendly website. Quickbooks pro software application is accessed on desktop, mobile and tablet.
Inviato da: pinky singh il: 2019-02-07 12:28:03.680954 I definitely enjoying every little bit of it and I have you bookmarked to check out new stuff you post. Food Sources of Probiotics
Inviato da: Food Sources of Probiotics il: 2018-09-05 12:57:16.244999 MauveTree is a fashion stores which offers premium quality of leather jackets both for men & women. Go, Have a look now! [url=https://www.mauvetree.com/]MauveTree[/url]
Inviato da: Emma Jason il: 2018-09-25 22:48:40.264929 amazing post man
Inviato da: giant-huntsman-spider-largest-spider-in-australia/">huntsman spider facts il: 2018-09-14 20:56:53.623714 Dziękuję za informacje! Szukałem i nie mogłem znaleźć. Pomogłeś mi! green dot bank phone number
Inviato da: Sophie Miller il: 2018-11-02 10:17:01.278137 amazing post man icloud login email
Inviato da: icloud login email il: 2018-09-14 20:00:16.066977 Good Job free aptoide apk installer and download
Inviato da: Rachel il: 2018-09-26 14:36:40.667181 Mcafee.Com/Activate, Mcafee.Com/Retailcard - McAfee antivirus tool which is very useful for those, who need to get amazing security provider for their personal computer. You can get more features and enhanced services of protection against malicious attacks. Www.Mcafee.Com/Maa/Retailcard
Inviato da: Www.Mcafee.Com/Intelchannel | Www.Mcafee.Com/Mav/Retailcard il: 2018-12-25 07:22:49.165484 QuickBooks Support - Dial QuickBooks Technical Support Phone Number 1-888-412-7852 and directly talk to Certified QB experts to fix all issues related to QuickBooks. Quickbooks Online Support | Quickbooks for Mac Support | QuickBooks Desktop Support | QuickBooks Enterprise Support | Quickbooks POS Support | QuickBooks Payroll Support | QuickBooks Error Support
Inviato da: quickbooks support number il: 2019-01-10 08:31:37.458906 good info Achieve3000 Sign in
Inviato da: Rachel il: 2018-09-26 15:47:14.962904 With the rapid increase in the number of viruses in the digital world, there has been observed a great demand in the smarter security solutions. These security solutions, including antivirus and WiFi privacy are needed to deal with all kinds of online threats that can not only corrupt or damage your data, but also steal your confidential information, resulting in loss of your hard-earned money.
Inviato da: KASPERSKY SUPPORT il: 2019-01-31 10:00:03.424619 These electrical items are needed in the home
Inviato da: slither io il: 2018-10-26 10:09:57.210179 nice blog regarding the article..
Inviato da: Phd Thesis Writing Services il: 2019-02-27 12:27:20.252097 Instagram is available for free on iOS and Android devices. Get start with Instagram video downloader now.
Inviato da: John Lennon il: 2019-02-26 04:08:16.444452 Www.Office.Com/Myaccount, Office.Com/Myaccount - Let's Connect with our skilled MS Office setup experts via Email, call or live chat and get instant and immediate support for any Office.Com/Setup related query. We choose to solve your issues remotely so your time and money can be saved. Office.Com/Myaccount
Inviato da: Microsoft Office Setup | Www.Office.Com/ Setup il: 2018-12-25 07:13:58.625843 This is really an amazing article. Your article is really good and your article has always good content with a good powerpoint with informative information. norton.com/setup mcafee.com/activate office.com/setup
Inviato da: norton.com/setup il: 2019-03-09 19:02:48.58824 Quickbooks Errro Support Number Facing critical issues, instant dial QuickBooks errors technical help number 1.888.986.7735 & get 24x7 experts assistance to fix errors related to QB installation, upgradation, unrecoverable & many more. QuickBooks POS Support | QuickBooks Premier Support | QuickBooks Pro Support | QuickBooks Error Support
Inviato da: Quickbooks Pro Support il: 2019-01-10 08:30:43.943938 This is a fantastic website , thanks for sharing. Healthy Hair
Inviato da: Healthy Hair il: 2018-09-05 12:46:03.2897 No matter what type of assignment you have at hand you may easily seek the help of online assignment help UK at just one click. When university students get worried about their ever increasing academic activities and the constant shortage of time they develop a feeling of helplessness that can only be removed by the excellent writers working with Top Assignment Help In UK.
Inviato da: Justin Smith il: 2018-09-10 07:50:14.192757 Thanks for sharing this piece of information. I really enjoyed it. keep up the good work and all the very best of luck! Detriot Become Human Game Jacket
Inviato da: Emma Jason il: 2018-10-05 20:03:15.377689 Open Office.com/setup is totally allowed to utilize, simply download it on your PC or PC and you are a great idea to go. It stores every one of your information in a universal open standard configuration and can likewise peruse and compose records from other basic office programming bundles.
Inviato da: Office.com/setup il: 2019-03-12 07:14:08.169511 KK Air Freight Services Pvt. Ltd.help to deliver your product Domestic & International Courier & Cargo Agents service, logistics, air freight forwarding, parcel services companies in Andheri east and west Mumbai. International forwarders services for the USA, UK, Singapore, Australia.
Inviato da: Cheap International Courier Mumbai il: 2019-03-13 13:29:44.981176 Intersting details about a modam here you know you could buy them way cheaper from uk courseworks and it could also be linked to some of your work profile here, so think about investing in there and moving up on the ladder with it !
Inviato da: Patton il: 2018-08-18 13:09:42.841229 I modem ADSL sono generalmente dispositivi esterni, la tecnologia necessaria è difficilmente compattabile in schede interne. Leggi manga online gratuitamente in alta qualità e più completa a Mangafox
Inviato da: Mangafox il: 2018-05-28 16:18:30.376664 Download and install your Norton product. Sign In to Norton. If you do not have a Norton account, click Create account and complete the sign up process. In the Norton Setup window, click Enter a New Product Key. To enroll in Automatic Renewal Service for your Norton subscription, Get Started
Inviato da: norton.com/setup il: 2019-03-08 22:08:45.67285 Thank you so much for sharing these amazing tips. I must say you are an incredible writer, I love the way that you describe the things. Please keep sharing.
Inviato da: Charlie Noah il: 2019-01-24 19:57:31.317437 Very nice article, I enjoyed reading your post, very nice share, I want to twit this to my followers. Thanks!. Foods That Cause Inflammation
Inviato da: Foods That Cause Inflammation il: 2018-09-05 10:21:36.957267 you need to enact or restore your membership before the preliminary or membership sum finishes to at present utilize the majority of the Norton.com/setup alternatives and keep your pc secured.
Inviato da: norton.com/setup il: 2019-03-12 05:37:38.748541 Wonderful illustrated information. I thank you about that. No doubt it will be very useful for my future projects. Would like to see some other posts on the same subject! Perilla Seed Oil
Inviato da: Perilla Seed Oil il: 2018-09-05 13:19:11.179905 Amazing best cloud storage service
Inviato da: best cloud storage service il: 2018-10-23 19:35:46.397923 amazing post man Make Google My Homepage in Windows 10
Inviato da: Make Google My Homepage in Windows 10 il: 2018-09-14 19:34:07.167823 amazing post man
Inviato da: Make Google My Homepage in Windows 10 il: 2018-09-14 19:32:25.410577 thanks for this website it's really helpful https://games.lol/racing/
Inviato da: adamsnow il: 2019-01-08 02:30:41.223134 HP Printer Support – HP Inc. is American Multinational Information Technology Company engaged in manufacturing a wide range of hardware and software components along with allied services to the consumers and businesses. From laptops, desktops, tablets, storage devices to peripheral devices, it offers all types of tech products. Like all HP products, its printing range has also gained immense popularity among the customers due to its exceptional features, like excellent print quality, incredible speed, easy to operate and superior performance. HP printers are manufactured using the latest technology in order to deliver the best printing experience to the customers. Most common HP printers for home and offices include:
Inviato da: HP Printer Support il: 2019-01-18 06:44:33.489995 Economicskey Provides Quality Economics Homework Help For Students.
Inviato da: Harvard Ocean Carriers Case solution il: 2018-10-29 07:48:24.214744 Download and install your Norton product.
Inviato da: norton setup il: 2019-03-08 22:09:36.01369 mcafee.com/activate- Activate, Install, Download and Renew Your Product With Live Support. Setup Your Product, Activate Your Product, Install Your Product With 3 Setup.
Inviato da: mcafee.com/activate il: 2019-01-25 08:11:50.447449 McAfee.com/Activate- McAfee is a leading cybersecurity brand that offers total protection a wide selection of security software and anti-viruses to protect devices and the internet network from viruses, spyware, phishing attacks, scams, and hacking attacks. To make the most out of McAfee protection, buy a suitable antivirus from mcafee.com/activate and then install and activate it using a 25-digit McAfee activate product key.
Inviato da: mcafee activate il: 2019-01-17 08:25:48.62311 Great website helps a lot. Amazing articles
Inviato da: norton.com/setup il: 2019-03-17 15:59:38.866776 Norton by Symantec offers an array of security suites.The web inclined world structures the need of an antivirus that can secure your information and furthermore guarantee safe looking at and what's more ensured exchanges over the web.
Inviato da: norton.com/setup il: 2019-03-07 12:34:34.309213 Avg.Com/Registration, Avg.Com/Retail - Dial the AVG Antivirus Customer support phone number to get quick help and solutions to the problems over the phone. Seek immediate customer service for AVG antivirus. Www.Avg.Com/Retail
Inviato da: AVG Support Phone Number | AVG Technical Support il: 2018-12-25 07:19:17.508675 amazing post man article spinner
Inviato da: article spinner il: 2018-09-14 20:11:20.255762 Thank you so much for sharing these amazing tips. I must say you are an incredible writer, I love the way that you describe the things. Please keep sharing. For more information visit on office.com/setup | office.com/setup | office.com/setup | Norton.com/setup
Inviato da: norton.com/setup il: 2018-12-27 09:47:21.983987 Great website helps a lot. Amazing articles
Inviato da: norton.com/setup il: 2019-03-17 16:02:09.018384 Www.Office.Com/Setup, Office.Com/Setup - We are a Microsoft Office setup support provider to offer full-fledged technical support for those users who have any sort of issues concerning about MS Office applications. Www.Office.Com/ Setup
Inviato da: Www Office Com Setup | Office Support Number il: 2018-12-25 06:54:30.361747 SPG Tech soft is one of the most leading website designing and development company. it's an E-Commerce Website Designing and Development Company based in Andheri Mumbai. we offer website development and designing service with the best price.
Inviato da: Web designing company in Mumbai il: 2019-03-13 13:24:34.591695 Good Job free Cloud storage 2018
Inviato da: Rachel il: 2018-09-26 15:33:27.985133 Its good Achieve3000 Sign in
Inviato da: Rachel il: 2018-09-26 15:45:01.527503 Your information is really help me. Thanks for advance, and I will bookmark it now!
Inviato da: bubble shooter il: 2018-10-31 08:11:56.528244 AOI Tech Solutions is a best internet and network security providing company in US, UK, Canada and Australia. Higher customer satisfaction and affordable services. Trained experts with lot of experience. For more details call us - 888-875-4666.
Inviato da: John il: 2019-01-29 18:03:47.835265 Great https://achieve3000loginz.com/
Inviato da: https://achieve3000loginz.com/ il: 2018-10-23 19:51:41.208386