Smt frame classes and types – Sun Microsystems 1.0 User Manual

Page 126

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SunFDDI/P 1.0 Adapter User’s GuideMay 1997

8

SMT Frame Classes and Types

SMT frames are used for peer-to-peer (station-to-station) management. They
are divided into classes, which define the function of the frame. Each class is
then divided into up to three types, which define whether the frame is an
announcement (information only), a request for service, or a response to a
request. Refer to the ANSI/FDDI Station Management (SMT) X3.299 R7.3
Specification
for a detailed description of

SMT

frames and their functions.

The

pf_smtmon

utility is used to monitor the following SMT frame classes:

NIF (Neighbor Information Frames)

These are the most common frames displayed when you run

pf_smtmon

. As

the name suggests, they carry information about a neighboring station (for
example, address, description, state,

MAC

capabilities) and are used as

keep-alive notifications that a station is still attached to the ring and
functioning. An

NIF

frame can be an announcement, a request, or a response.

SIF (Status Information Frames)

These frames carry more detailed information about a station.

SIF

configuration frames describe the station configuration (for example, number
of ports, number of

MAC

entities, connection policy);

SIF

operation frames

describe the current status of the station. A

SIF

frame can be either a request

or a response.

ECF (Echo Frames)

These frames are equivalent to ICMP

ping

packets and are used to test

connectivity between stations. An

ECF

frame can be either a request or a

response.

RDF (Request Denied Frame)

These frames are used to indicate that the request is rejected. If an

SMT

agent

(such as the SunNet Manager proxy agent delivered with SunFDDI/P) receives
an unsupported or unrecognized request, it issues an

RDF

frame to indicate

that the request is rejected. An

RDF

frame is always a response.

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