z/OS Communications Server

z/OS® Communications Server provides Application Programming Interfaces (APIs) and networking protocol support to enable SNA and TCP/IP applications running on z/OS to communicate with partner applications or users on the same system, other systems within a single data center, or in distant locations. The main features of z/OS Communications Server are in the areas of:

• 1. High-Bandwidth and High-Speed networking technologies

• 2. High Availability

• 3. Enterprise Connectivity

• 4. System and Data Security

• 5. Network Management

Learn what's new in z/OS Communications Server V1R4 and V1R5.

High Speed Connectivity: Communications Server provides support for High-Bandwidth and High-Speed networking technologies.

• Gigabit Ethernet with OSA Express QDIO for TCP/IP

• High-speed communication between TCP/IP stacks running in a z/OS logical partition (LPAR) using Hypersockets

High Availability: Communications Server provides high availability to z/OS applications over both SNA and TCP/IP networks. z/OS Parallel Sysplex® technology is utilized to enable high availability application support.

• APPN High Performance Routing (HPR) provides end-to-end session continuity by supporting non-disruptive path switch around failed network components

• SNA Generic Resources function provides workload balancing for multi-instance applications within a parallel Sysplex in order to maximize availability and efficiency of application data sharing

• Multi-node Persistent Sessions provides session recovery for SNA applications

• Dynamic VIPA (Virtual IP Address) provides TCP/IP application availability across z/OS systems in a Sysplex and allows participating TCP/IP stacks on z/OS to provide backup and recovery for each other for both planned or unplanned TCP/IP outages

• Sysplex Distributor provides intelligent load balancing for TCP/IP application servers in a Sysplex and, along with Dynamic VIPA, provides a single system image for client applications connecting to these servers

Enterprise Connectivity: Communications Server includes many features that support Enterprise Connectivity.

• Tn3270 Server provides workstation connectivity over TCP/IP networks to access z/OS and enterprise SNA applications

• Enterprise Extender allows SNA Enterprise applications to communicate reliably over an IP network using SNA HPR and UDP transport layer protocols

• APPN Extended Border Node (EBN) provides a replacement for 3745/NCP based SNA Network Interconnect (SNI)

Network Security: Network Security protects sensitive data and the operation of the TCP/IP stack on z/OS.

• IPSEC/VPN functions enable the secure transfer of data over a network using standards for encryption, authentication, and data integrity
• Intrusion Detection Services (IDS) evaluates the stack for attacks that would undermine the integrity of its operation. Events to examine and actions to take (e.g., logging) at event occurrence are defined by IDS policy which is downloaded from an LDAP server
• TLS/SSL enablement for key applications ensures data is protected as it is flowing across the network(s):
  • FTP client and server
  • TN3270 server
• Kerberos5 and GSSAPI support is provided for the following applications:
  • FTP client and server
  • Unix rshd server
  • Unix System Services telnet server (supports only Kerberos5)

Network Management: Network Management support collects network topology, status and performance information and makes it available to network management tools.

• VTAM supports the traditional Common Management Information Protocol (CMIP) network management protocol for managing SNA network topology along with providing other management interfaces for performance monitoring

• Managing TCP/IP, the SNMPv3 protocol is supported

• Communications Server provides support for standard SNMP applications and also for IETF standard TCP/IP protocol MIBs

• Additional MIB support is also provided by the IBM MVS® TCP/IP Enterprise-specific MIB which supports management data for Communications Server TCP/IP stack-specific functions