> For the complete documentation index, see [llms.txt](https://docs.editran.onesait.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.editran.onesait.com/documentacion-editran/ibm-editran-v5.3-cics-en/tcp/introduction.md).

# Introduction

For the installation, the definitions corresponding to TCPIP V3R2 and editran 4.1 were followed. The minimum requirements are: 

OS/390 R3 or OS/390 V2R4

TCP/IP Version 3 Release 2 requires CICS/ESA Version 3.3 or later (preferably 4.1).

TCP/IP for MVS Version 3 Release 2 or later.

MVS/ESA Version 4.3 or higher.

In TCP/IP 3.2 (for OS/390 2.3 and 2.4), make sure you have the “Release 32C", TCP/IP 3.2 for MVS with the "Enhancements Kit", FMID JTCP32C.

editran has used the Sockets Extended API programming style (COBOL, PL/I, Assembler Language).

Note: Some of the security features require CICS/ESA 4.1 or higher.

The CICS must be defined (name of the started task) and the default group it belongs to, in the OMVS segment.

```
DEFINE USER CICSSITD OMVS (UID (0) HOME (‘/’)
DEFINE GROUP STCUSR OMVS (GID (4))
```

Documentation on ERRNO, RETCODE, and error messages in TCPCICS, provided by the macros used for EXTENDED SOCKETS, is available in appendix C of the IBM TCP/IP for MVS CICS TCP/IP Socket Interface Guide and Reference manual. Document Number SC31-7131-03. Program number 5655 HAL. File Number S370/4300/30xx-50. See also Document Number: SC31-8518-00. If the corresponding error does not appear, the error may be related to OS390 V2R5 OPEN EDITION, so it is included in F1AF9000 IP Planning and Migration Guide.

Editran can operate simultaneously with several types of connection (editran/PR and TCP/IP. If a transmission session is defined with connection type tcp, the remote end must have its session with tcp. IP connections on the host go through the OSA defined in the TCP stack.

Before installing editran, the sockets for CICS must be installed.

## Knowledge of IP connectivity <a href="#toc149150249" id="toc149150249"></a>

The purchase of editran TCP/IP (as with any communications product) does not guarantee editran connectivity between endpoints. To connect with editran TCP/IP, it is necessary:

That the remote endpoint has editran TCP/IP

That IP connectivity (not to be confused with editran TCP/IP, which does not present any problem) is possible on the line used; that is, that both ends “know” and agree on the type of line to use: internet, frame relay lines, private lines, within a network, etc.&#x20;

## Problems detected <a href="#toc149150250" id="toc149150250"></a>

Problems have been detected with Packteer's Packet Shaper equipment. This product is able to recognize traffic, prioritize it by protocols, classify it, marking ports that it may consider dangerous, and discard packets in certain situations. The detected problems consist in the fact that sometimes the connection and transmission is achieved in one direction, but in the reverse direction, normally when the call is made by the endpoint that has this equipment on its network, the connection reaches the remote endpoint, which accepts it, but that acceptance does not reach the calling endpoint (discarding said packet). To solve the problem, some entity told us that a class exception was configured on that machine, a rule placed before classifying the protocol; ultimately, allowing certain IP addresses.

&#x20;


---

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