如何使用Telnet登錄IBM iSeries AS/400

Question

我正在嘗試開發一個應用程序，如IBM iSeries AS/400的終端仿真。我正在使用AsyncSocket連接到服務器。連接是好的，但我應該如何登錄連接建立後使用用戶名和密碼的Telnet服務器。有什麼格式或命令或方式，我應該將用戶名和密碼發送到服務器登錄。

Answer 1

聽起來你很想仔細研究RFC 4777 - RFC 4777 - IBM's iSeries Telnet Enhancements。

注特別是對「標準進行Telnet選項協商」一節：

Telnet server option negotiation [RFC855] typically begins with the 
issuance, by the server, of an invitation to engage in terminal type 
negotiation with the Telnet client (DO TERMINAL-TYPE) [RFC1091]. The 
client and server then enter into a series of sub-negotiations to 
determine the level of terminal support that will be used. After the 
terminal type is agreed upon, the client and server will normally 
negotiate a required set of additional options (EOR [RFC885], BINARY 
[RFC856], SGA [RFC858]) that are required to support "transparent 
mode" or full screen 5250/3270 block mode support. As soon as the 
required options have been negotiated, the server will suspend 
further negotiations and begin with initializing the actual virtual 
device on the iSeries. A typical exchange might start as follows: 

iSeries Telnet server    Enhanced Telnet client 
--------------------------  ------------------------- 
IAC DO TERMINAL-TYPE  --> 
          <-- IAC WILL TERMINAL-TYPE 
IAC SB TERMINAL-TYPE SEND 
IAC SE      --> 
            IAC SB TERMINAL-TYPE IS 
          <-- IBM-5555-C01 IAC SE 
IAC DO EOR     --> 
          <-- IAC WILL EOR 
          <-- IAC DO EOR 
IAC WILL EOR    --> 


Actual bytes transmitted in the above example are shown in hex below. 

iSeries Telnet server    Enhanced Telnet client 
--------------------------  ------------------------- 
FF FD 18     --> 
          <-- FF FB 18 
FF FA 18 01 FF F0   --> 
            FF FA 18 00 49 42 4D 2D 
            35 35 35 35 2D 43 30 31 
          <-- FF F0 
FF FD 19     --> 
          <-- FF FB 19 
          <-- FF FD 19 
FF FB 19     --> 

所以你真的想尋找那些字節碼併發送相應的響應。