Envoy Configuration and Management Manual

Envoy Configuration and Management Manual—429861-001

D-1

S-Series Changes to Envoy

The NonStop Himalaya S-series server architecture affects I/O processes such as Envoy

because a single data-communications concentrator replaces all former communications

controllers. In addition, the management subsystem that controls the concentrator

required changes to configuration operations. These basic changes mostly affect

SYSGEN configuration and SCF.

NonStop Himalaya S-Series Server Architecture

The ServerNet wide area network (SWAN) concentrator on NonStop Himalaya S-series

servers replaces the 3602 byte-synchronous and the 3603 asynchronous controllers.

Envoy communicates with the SWAN concentrator to a data link control (DLC) task

which runs in the SWAN concentrator. There are two DLC tasks: WANENVBSC and

WANENVASC. The WANENVBSC DLC task uses the WAN byte driver, emulating the

3602 controller for NonStop Himalaya K-series servers, and the WANENVASC DLC

task uses the WAN ASYNC driver, emulating the 3603 controller for NonStop Himalaya

K-series servers. The WAN driver provides an interface to the WAN ports on the CLIP

(communications line interface processor). For more information about the SWAN

concentrator, refer to the WAN Subsystem Configuration and Management Manual.

Subsystems running in the NonStop Kernel, such as Envoy, access the SWAN

concentrator through Compaq NonStop TCP/IP and the ServerNet LAN Systems Access

(SLSA) subsystems.

The CLIP is the major programmable device within the SWAN concentrator, providing

link-level protocol and a software interface to the server. The CLIP stores and

implements specific communications protocols. There are three CLIPs on one SWAN

concentrator. Each CLIP contains a Motorola MC68EN360 quad integrated

communications controller (QUICC) chip. Each CLIP interfaces to both the A and B

Ethernet ports and has two WAN ports.

G-Series Migration Considerations

This subsection lists the differences between D-series and G-series versions of Envoy.

CBSENSEON and CFSENSEON Modifiers

D-series versions of Envoy

FDX, NAQ read lines do not monitor MODEM signals while a READ is in progress. In

other words, SYSGEN modifiers CBSENSEON and CFSENSEON are not used.

G-series versions of Envoy

CBSENSEON and CFSENSEON are used even for FDX and NAQ lines. In other

words, FDX and NAQ lines also monitor MODEM signals while a READ is in progress.