| ==Phrack Inc.== |
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|
| Volume Two, Issue 18, Phile #3 of 11 |
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| _ _ _ _ _____________________________________________ _ _ _ _ |
| _-_-_-_- -_-_-_-_ |
| _-_-_-_- An Introduction To -_-_-_-_ |
| _-_-_-_- -_-_-_-_ |
| _-_-_-_- Packet Switched Networks -_-_-_-_ |
| _-_-_-_- -_-_-_-_ |
| _-_-_-_- -_-_-_-_ |
| _-_-_-_- -_-_-_-_ |
| _-_-_-_- Written By - Revised - -_-_-_-_ |
| _-_-_-_- -_-_-_-_ |
| _-_-_-_- Epsilon 05/3/88 -_-_-_-_ |
| _-_-_-_-_____________________________________________-_-_-_-_ |
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| Preface - |
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|
| In the past few years, Packet Switched Networks have become a prominent |
| feature in the world of telecommunications. These networks have provided ways |
| of communicating with virtually error-free data, over very large distances. |
| These networks have become an imperative to many a corporation in the business |
| world. In this file we will review some of the basic aspects of Packet |
| Switched Networks. |
|
|
| Advantages - |
|
|
| The Packet Switched Network has many advantages to the common user, and |
| even more to the hacker, which will be reviewed in the next topic. |
|
|
| The basis of a Packet Switched Network is the Packet Switch. This network |
| enables the service user to connect to any number of hosts via a local POTS |
| dial-up/port. The various hosts pay to be connected to this type of network, |
| and that's why there is often a surcharge for connection to larger public |
| services like Compuserve or The Source. |
|
|
| A Packet Switched Network provides efficient data transfer and lower rates |
| than normal circuit switched calls, which can be a great convenience if you |
| are planning to do a lot of transferring of files between you and the host. |
|
|
| Not only is the communication efficient, it is virtually error free. |
| Whereas in normal circuit switched calls, there could be a drastic increase in |
| errors, thus creating a bad transfer of data. |
|
|
| When using a Packet Switched Network, it is not important that you |
| communicate at the same baud rate as your host. A special device regulates |
| the speed so that the individual packets are sped up or slowed down, according |
| to your equipment. Such a device is called a PAD (Packet Assembler |
| Disassembler). |
|
|
| A PSN also provides access to a variety of information and news retrieval |
| services. The user pays nothing for these calls, because the connections are |
| collect. Although the user may have to subscribe to the service to take |
| advantage of it's services, the connection is usually free, except for a |
| surcharge on some of the larger subscription services. |
|
|
| Advantages To Hackers - |
|
|
| Packet Switched Networks, to me, are the best thing to come along since the |
| phone system. I'm sure many other hackers feel the same way. One of the |
| reasons for this opinion is that when hacking a system, you need not dial out |
| of your LATA, using codes or otherwise. |
|
|
| Now, the hacker no longer has to figure out what parameters he has to set |
| his equipment to, to communicate with a target computer effectively. All |
| PSSes use the same protocol, set by international standards. This protocol is |
| called X.25. This protocol is used on every network-to-network call in the |
| world. |
|
|
| When operating on a packet switch, you are not only limited to your own |
| network (As if that wasn't enough already). You can access other PSSes or |
| private data networks through gateways which are implemented in your PSN. |
| There are gateways to virtually every network, from virtually every other |
| network, except for extremely sensitive or private networks, in which case |
| would probably be completely isolated from remote access. |
|
|
| Another advantage with PSNs is that almost everyone has a local port, which |
| means if you have an outdial (Next paragraph), you can access regular circuit |
| switched hosts via your local Packet Switched Network port. Since the ports |
| are local, you can spend as much time as you want on it for absolutely no |
| cost. So think about it. Access to any feasible network, including overseas |
| PSNs and packet switches, access to almost any host, access to normal circuit |
| switched telephone-reachable hosts via an outdial, and with an NUI (Network |
| User Identity - Login and password entered at the @ prompt on Telenet), |
| unlimited access to any NUA, reverse-charged or not. |
|
|
| Due to the recent abuse of long distance companies, the use of codes when |
| making free calls is getting to be more and more hazardous. You may ask, 'Is |
| there any resort to making free calls without using codes, and without using a |
| blue box?' The answer is yes, but only when using data. With an outdial, |
| accessible from your local PSN port, you can make data calls with a remote |
| modem, almost always connected directly to a server, or a port selector. This |
| method of communicating is more efficient, safer, and more reliable than using |
| any code. Besides, with the implementation of equal access, and the |
| elimination of 950 ports, what choice will you have? |
|
|
| Some Important Networks - |
|
|
| As aforementioned, PSNs are not only used in the United States. They are |
| all over the place. In Europe, Asia, Canada, Africa, etc. This is a small |
| summary of some of the more popular PSNs around the world. |
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|
| Country Network Name *DNIC |
| ~~~~~~~ ~~~~~~~ ~~~~ ~~~~ |
| Germany Datex-P 2624 |
| Canada Datapac 3020 |
| Italy Datex-P 0222 |
| South Africa Saponet 0655 |
| Japan Venus-P 4408 |
| England Janet/PSS 2342 |
| USA Tymnet 3106 |
| USA Telenet 3110 |
| USA Autonet 3126 |
| USA RCA 3113 |
| Australia Austpac 0505 |
| Ireland Irepac 2724 |
| Luxembourg Luxpac 2704 |
| Singapore Telepac 5252 |
| France Transpac 2080 |
| Switzerland Telepac 2284 |
| Sweden Telepac 2405 |
| Israel Isranet 4251 |
| ~~~~~~~~~ ~~~~~~~ ~~~~ |
| * - DNIC (Data Network Identification Code) |
| Precede DNIC and logical address with a |
| '0' when using Telenet. |
| ______________________________________________________________________________ |
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| Notes On Above Networks - |
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|
| Some countries may have more than one Packet Switching Network. The ones |
| listed are the more significant networks for each country. For example, the |
| United States has eleven public Packet Switching Networks, but the four I |
| listed are the major ones. |
|
|
| Several countries may also share one network, as shown above. Each country |
| will have equal access to the network using the basic POTS dial-up ports. |
|
|
| Focus On Telenet - |
|
|
| Since Telenet is one of the most famous, and highly used PSNs in the United |
| States, I thought that informing you of some of the more interesting aspects |
| of this network would be beneficial. |
|
|
| Interconnections With Other Network Types - |
|
|
| Packet Switched Networks are not the only type of networks which connect a |
| large capacity of hosts together. There are also Wide Area Networks, which |
| operate on a continuous link basis, rather than a packet switched basis. |
| These networks do not use the standardized X.25 protocol, and can only be |
| reached by direct dial-ups, or by connecting to a host which has network |
| access permissions. The point is, that if you wanted to reach, say, Arpanet |
| from Telenet, you would have to have access to a host which is connected to |
| both networks. This way, you can connect to the target host computer via |
| Telenet, and use the WAN via the target host. |
|
|
| WANs aren't the only other networks you can access. Also, connections to |
| other small, private, interoffice LANs are quite common and quite feasible. |
|
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| Connections To International NUAs via NUIs - |
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|
| When using an NUI, at the prompt, type 0+DNIC+NUA. After your connection |
| is established, proceed to use the system you've reached. |
|
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| Private Data Networks - |
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|
| Within the large Packet Switched Networks that are accessible to us there |
| are also smaller private networks. These networks can sometimes be very |
| interesting as they may contain many different systems. A way to identify a |
| private network is by looking at the three digit prefix. Most prefixes |
| accessible by Telenet are based on area codes. Private networks often have a |
| prefix that has nothing to do with any area code. (Ex. 322, 421, 224, 144) |
| Those prefixes are not real networks, just examples. |
|
|
| Inside these private networks, there are often smaller networks which are |
| connected with some type of host selector or gateway server. If you find |
| something like this, there may be hosts that can be accessed only by this port |
| selector/server, and not by the normal prefix. It is best to find out what |
| these other addresses translate to, in case you are not able to access the |
| server for some reason. That way, you always have a backup method of reaching |
| the target system (Usually the addresses that are accessed by a gateway |
| server/port selector translate to normal NUAs accessible from your Telenet |
| port). |
|
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| When exploring a private network, keep in mind that since these networks |
| are smaller, they would most likely be watched more closely during business |
| hours then say Telenet or Tymnet. Try to keep your scanning and tinkering |
| down to a minimum on business hours to avoid any unnecessary trouble. |
| Remember, things tend to last longer if you don't abuse the hell out of them. |
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| Summary - |
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|
| I hope this file helped you out a bit, and at least gave you a general idea |
| of what PSNs are used for, and some of the advantages of using these networks. |
| If you can find something interesting during your explorations of PSNs, or |
| Private Data Networks, share it, and spread the knowledge around. Definitely |
| exploit what you've found, and use it to your advantage, but don't abuse it. |
|
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| If you have any questions or comments, you reach me on - |
|
|
| The FreeWorld II/Central Office/Forgotten Realm/TOP. |
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|
| I hope you enjoyed my file. Thanks for your time. I should be writing a |
| follow up article to this one as soon as I can. Stay safe.. |
|
|
| - Epsilon |
| ______________________________________________________________________________ |
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|
| - Thanks To - |
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|
| Prime Suspect/Sir Qix/The Technic/Empty Promise/The Leftist |
| ______________________________________________________________________________ |
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|
