Envoy ACP/XF Configuration and Management Manual

Introduction to EnvoyACP/XF
EnvoyACP/XF Configuration and Management Manual—429232-003
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ServerNet WAN Concentrator
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 and each CLIP supports two serial ports. The resulting six lines can
support any combination of the following interfaces:
•
RS-232
•
RS-449
•
V.35
•
X.21
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.
The configuration rules enable any I/O protocol to share a CLIP with any other I/O
protocol; all combinations are fully supported.
ServerNet WAN Concentrator
The ServerNet WAN (SWAN) concentrator provides access to wide area networks on
NonStop S-series servers and Integrity NonStop NS-series servers. The SWAN
concentrator as it relates to EnvoyACP/XF is described in this subsection.
When an application transmits and receives data, the ServerNet WAN concentrator
handles some parts of the bit-synchronous frame format automatically.
When an application transmits data, the ServerNet WAN concentrator performs the
following functions:
•
Generates opening and closing flags
•
Generates the frame-check sequence
•
Performs zero-bit insertion
When an application receives data, the ServerNet WAN concentrator performs the
following functions:
•
Recognizes and strips the flag fields
•
Verifies data using the frame-check sequence field
•
Deletes the inserted zero bits