Chapter 184 Instant Messaging Software

After the website went online, Matthew, Arthur and Pison told the news to their friends they often contact. Because they were not very popular in school before, most of their friends also met on technical BBS.

However, Matthew and others still underestimated everyone's expectations for the official BBS of the SAM Association.

At 12:30 p.m., Lin Hong suddenly found that the TELNET client could not connect to the server.

"Have you been invaded?" This is Lin Hong's first thought.

The information prompted above mainly means that the service is denied due to the number of connections.

He tried several times and found that it was still the same.

At this time, Arthur knocked on his door again, and was told that it was the same on his side.

There are two possibilities in this situation. One is that the server is hacked, causing the server to refuse service, and the other is that the number of people really visits is too large, and the server is overloaded to bear the access of so many people.

Arthur quickly called Matthew and asked about his situation. As a result, he said he could visit, but the speed was very slow.

After trying several times, Lin Hong finally logged in again, and the speed of content refresh is indeed very slow.

Then, Arthur asked him to log in to the management background of BBS and looked at the statistics. The results showed that more than 1,000 people were online at the same time.

The result is very clear. The website failed because there were too many visitors at one time, and the server had only one line, and it could not afford so many people to refresh the access at the same time, which prompted an error.

They didn't expect it at all, just because they and their friends had advertised their website before, and as a result, everyone poured in.

This situation surprised and delighted the members of the SAM team. Matthew is already considering whether it is necessary to add more lines.

Fortunately, this wave of traffic came and went quickly, and soon BBS returned to normal access. At this time, there have been many replies and new posts in the forum.

In particular, the tutorial released by Lin Hong was praised by many people. Many people said that in response to Lin Hong's call, they began to crack other calculators in their hands that were not the Texas Instrument brand.

In the next few days, the SAM team began to expand slowly.

Many people have submitted their works in the forum and hope to join the SAM Association and become a member of this group.

However, Matthew's control over his members is quite strict. Among the dozens of people who met the standard, only five people were selected, and then an association meeting was held. Everyone discussed these five people. After eliminating two more people, the SAM Association had seven members.

Considering that there are few people who understand hardware, two of the newly added three are more proficient in hardware. And none of these three are members of the Latin School, and one of them is a college student at the Massachusetts Institute of Technology.

Thanks to the participation of others, Lin Hong's work has been greatly reduced. He has been studying the content of instant messaging software these days.

Last time he noticed that it was a little difficult for him to communicate with several other members because of the different system platforms, because his computer operating system is Microsoft's DOS, while the other three are from Apple, and even the hardware architecture is different, not to mention the operating system and application software.

Now there are new members, and they are not from the same school. Usually, when they communicate, they have difficulties. There is an urgent need for a cross-platform instant chat software, and it is best to support multiple people chatting at the same time.

Lin Hong has been looking for information in this regard these days, mainly through school libraries and the Internet.

He learned that instant messaging software actually appeared as early as the 1960s. At the beginning, it appeared in multi-user operating systems, such as CTSS (compatible time-sharing) and Multics (the predecessor of Unix) operating systems.

In the beginning, the instant messaging function was developed as a system service, such as the "print" or "mail" process. Between ordinary users and system administrators, short messages or notifications are usually used for information exchange.

Later, it began to be used for communication between computers in the local area network. For example, when Lin Hong first had classes in the school computer room, Arthur hacked into his computer and used such a LAN communication function that came with the operating system.

After the rise of the Internet, these protocol communication protocols have been understood by more and more technicians, and some instant messaging software has gradually appeared on major mainstream operating systems. These software usage protocols can be basically divided into two protocol architectures. One is based on point-to-point, that is, the client and the client are directly connected, and the other type requires the client and the server to contact, and then the server for intermediate forwarding.

Point-to-point communication is relatively simple. Just like making a phone call, two people must be online at the same time to contact. If one party's network is not very good, or the other party is not online, the communication obviously cannot be carried out. Another point is that point-to-point communication can only be connected with one person at the same time.

The architecture of the server and client is similar to BBS. There is a special server as the "central hub", and everyone is in contact with this "central hub". For example, tell him that I want to send a message to so-and-so. Please forward it for me. In this way, even if the other party is not online at that time, when the other party is online, the server can send it to him. This is a delayed delivery.

Moreover, the second architecture also has another advantage, that is, group chat can be carried out, and one person can send messages to multiple people, making it possible to set up chat rooms.

The communication software called Xaric that Arthur and Matthew previously contacted is based on this architecture.

Lin Hong conducted a special research on this software and found that the protocol used by this software is the IRC protocol.

This protocol was developed by the Finn Yarkou * Oikalin in 1988. It is an Internet real-time text messaging protocol specially designed for internal communication between BBS or group members. It allows point-to-point, one-to-many, and even file sharing. The content.

Lin Hong learned about it and found that this protocol is public, that is to say, it is open to everyone for free, just like other common TCP/IP, UDP, FTP protocols, it can be used at will, whether for commercial and personal use.

Lin Hong admires him. In the history of the development of science and technology, I don't know how many such people have made contributions. From the initial electronic technology, radio technology, to modern telephone technology and computer technology, it is with the selfless dedication of these technical predecessors and the basic construction that can Gradually developed to today.

Lin Hong thought in his heart that after this software was written by himself, he would also use it for free for everyone and contribute his own strength.

Lin Hong went to the school library to look for it before, but he didn't see any information about the IRC agreement. Later, he asked Arthur and Matthew, and they didn't know where to find this information.

Later, he had to go to some technical forums to inquire. Finally, someone told him the address of a BBS discussion group. Lin Hong logged in to the discussion group and finally found the email address of the original author, so he tried to send an email to the original author Yaerkou, and Lin Hong made it clear in the email. He told him that he wanted to write a software based on the IRC protocol and wanted the details of the IRC protocol.

I had to wait for a while, but I didn't expect to receive a reply from the author in less than half an hour.

Yarkou is very happy that someone has joined the IRC protocol software development. For everyone, he will do his best to help others and provide convenience.

In the email, he sent Lin Hong detailed technical details of the protocol, including the latest upgraded version, including channel encryption and more convenient file sharing functions.

Originally, Lin Hong only wanted to write a communication software for communication within the team, so that only one server side was needed, and the rest were used as client-side and server-side connections.

However, after reading the latest IRC protocol of Yarkou, he decided to expand the software functions previously conceived, not limited to one server, but multiple, that is, integrating the server and client in the software at the same time. That is to say, every user can use himself as a relay server to provide services for everyone. In addition, there can also be connection between servers.

In fact, this architecture is very similar to amateur radio. In radio communication, there is a special radio station called "wireless relay station", which can relay and amplify the signal, thus extending the coverage of the radio network.

In the early days of radio invention, the long-distance propagation characteristics of short-wave signals have not been found, while medium- and long-wave radio ground-wave communication has a limited distance due to the loss of earth absorption. Early amateur radio enthusiasts expanded the range of communication through manual transit. The principle is the same as relay. Through the enthusiastic help of ham volunteers, hams can send radio signals to the other side of the ocean only through long waves. Even Lin Hong, the other end of the earth, decided to modify the structure, so that each client has the "relay station" function at the same time, which can greatly enhance the whole instant communication. Stability of the credit system. Because if there is only one server side, once the server has a problem for some reason, the communication between others will not be carried out at all.

The redesigned architecture will not be like this. If one of the nodes is damaged, the message can still be transmitted to the destination through the other node. There are countless paths for information transmission in theory, as long as the shortest one is found through the shortest path algorithm.

As for the language of writing this software, Lin Hong finally chose the C language. At the beginning, he considered the cross-platform needs. At present, among the high-level languages he has come into contact with, only the C language can meet this requirement.