Documentation

TCP MINDEV and RTO Defaults Changed

Two of the defaults in the TCPCFG00 file have changed.

For the TCP statement, the MINDEV parameter defaults to 40 (0.10 second).

Also on the TCP statement, the RTO parameter defaults to 0; range 0 - 6000.

APPEND Keyword for LUPOOL Statement

In configuration member APPLUP00, a new keyword, APPEND has been added to the LUPOOL statement.

LUPOOL NAME(pool_name)

APPEND(lu_name,...,lu_name)

Syntax Description

APPEND

Specifies additional LU names for an LUPOOL. When APPEND is specified with

 

a previously defined NAME, the LU names specified are appended to that

 

previously defined for LUPOOL. There is no limit to the number of LUPOOL

 

statements that can be specified with the APPEND keyword. Duplicate LU name

 

checking is done for the complete list of LU names (original and appended).

Example:

 

LUPOOL

NAME(VLTPOOL0)

LU(T20000,T20001,T20002,T20003,T20004,T20005,T20006,T20007,T20008)

LUPOOL NAME(VLTPOOL0) APPEND

LU(T20010,>T20011,T20012,T20013,T20014,T20015,T20016,T20017,T20018)

CDLC Considerations

The 3746-900 unit is configured with a network MTU size, but will override it with the lowest MTU size it encounters. That MTU size will be applied to whatever mainframe software will be running next. Therefore, if a small MTU size is used, that will become the restriction for subsequent IP packet sizes and may cause problems if fragmentation is not allowed. The CDLC MTU size should correspond to its network configuration parameter.

Recommendations on Setting TOS

The following recommendations for setting TOS (type of service) have been added to the Cisco IOS for S/390 Customization Guide.

When setting TOS, precedence bits should be set to zero.Of the next 4 bits, only one is to be set on in any one packet: 16 = mindelay, 8 = max thruput, 4 = reliability, 2 = min cost. These should be set as follows:

Telnet = 16

FTP Control = 16, Data = 8,

SMTP Commands = 16, Data = 8

DNS query = 16, zone transfer = 8

SNMP = 4

NNTP = 2

16Cisco IOS for S/390 Release 2.0 Release Notes

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Cisco Systems S/390 manual TCP Mindev and RTO Defaults Changed, Append Keyword for Lupool Statement, Cdlc Considerations

S/390 specifications

Cisco Systems S/390, also known as IBM's S/390 architecture, is a revolutionary mainframe computing solution that has significantly impacted enterprise computing since its introduction. Though primarily associated with IBM, its integration with Cisco Systems technologies has fostered enhanced networking capabilities, creating a robust platform for organizations to leverage.

One of the most notable features of the S/390 architecture is its scalability. The system is designed to manage workloads efficiently, enabling organizations to scale their operations seamlessly as their requirements grow. This architecture supports an extensive range of applications, from transaction processing to complex data analysis, making it suitable for diverse industries.

The S/390 systems are known for their reliability and resilience. With advanced error detection and correction mechanisms, the architecture minimizes downtime, ensuring that mission-critical applications remain operational. The mainframe's design accommodates redundancy and fault tolerance, reinforcing its reputation as a dependable computing solution.

Moreover, security is a core characteristic of the S/390 infrastructure. It incorporates various security features, such as encryption and robust access control mechanisms, to safeguard sensitive data against unauthorized access and cyber threats. This level of security is particularly critical for industries such as finance, healthcare, and government, where data protection is paramount.

The integration of Cisco networking technologies with the S/390 architecture brings enhanced connectivity and streamlined communication capabilities. Cisco’s advanced routing, switching, and security solutions bolster the mainframe's communication prowess, enabling organizations to create seamless, high-performance networks. This ensures that data flows efficiently between the mainframe and other networked devices.

Additionally, S/390 supports an array of middleware solutions, facilitating better interoperability with modern applications and cloud services. Organizations can take advantage of this flexibility to leverage existing investments in technology while embracing innovative solutions.

In summary, Cisco Systems S/390 embodies a potent combination of scalability, reliability, security, and advanced networking features. Its architecture serves as a cornerstone for enterprise computing, allowing organizations to meet their evolving business needs while maintaining high-performance standards. As businesses increasingly rely on data-driven decision-making, S/390 remains a critical asset for organizations striving for efficiency and innovation in their operations.