Communications Controller for Linux (Communications Controller for Linux on System z or CCL) is an IBM software product announced in 2005 that runs under

Linux on IBM Z Linux on IBM Z or Linux on zSystems is the collective term for the Linux operating system compiled to run on IBM mainframes, especially IBM Z / IBM zSystems and IBM LinuxONE servers. Similar terms which imply the same meaning are ''Linux/390'', ...

and emulates an

IBM 37xx IBM 37xx (or 37x5) is a family of IBM Systems Network Architecture (SNA) programmable communications controllers used mainly in mainframe environments. All members of the family ran one of three IBM-supplied programs. *''Emulation Program'' (E ...

communications controller. CCL runs unmodified

IBM Network Control Program The IBM Network Control Program, or NCP, was software that ran on a 37xx communications controller and managed communication with remote devices. NCP provided services comparable to the data link layer and Network Layer functions in the OSI mod ...

(NCP) to allow consolidation of an SNA network infrastructure to IP. According to IBM "SNA traffic enters and leaves CCL as SNA network flows over an OSA adapter. However, your wide area network infrastructure does not need to be SNA. You can consolidate your SNA traffic and use tunneling such as data link switching (DLSw) to encapsulate the SNA communication over an IP network." CCL supports

Ethernet Ethernet () is a family of wired computer networking technologies commonly used in local area networks (LAN), metropolitan area networks (MAN) and wide area networks (WAN). It was commercially introduced in 1980 and first standardized in 198 ...

and

Token Ring Token Ring network IBM hermaphroditic connector with locking clip. Screen contacts are prominently visible, gold-plated signal contacts less so. Token Ring is a computer networking technology used to build local area networks. It was introduc ...

local area network A local area network (LAN) is a computer network that interconnects computers within a limited area such as a residence, school, laboratory, university campus or office building. By contrast, a wide area network (WAN) not only covers a larger ...

(LAN) connectivity directly, and other connectivity through a DLSw router.

X.25 X.25 is an ITU-T standard protocol suite for packet-switched data communication in wide area networks (WAN). It was originally defined by the International Telegraph and Telephone Consultative Committee (CCITT, now ITU-T) in a series of drafts ...

requires IBM's NPSI software plus a third party package. CCL does not support

Bisync Binary Synchronous Communication (BSC or Bisync) is an IBM character-oriented, half-duplex link protocol, announced in 1967 after the introduction of System/360. It replaced the synchronous transmit-receive (STR) protocol used with second gener ...

or start-stop. According to IBM figures, CCL offers the performance of an "average 3745."

References

IBM mainframe operating systems Systems Network Architecture {{mainframe-compu-stub

Further reading

References