The success response messages for the port and VC statistics group
have the following format:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Version | Message Type | Result | Code |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Transaction Identifier |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Port |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| zero | VPI | VCI |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+ Input Cell Count +
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+ Input Frame Count +
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+ Input Cell Discard Count +
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+ Input Frame Discard Count +
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+ Input HEC Error Count +
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+ Input Invalid VPI/VCI Count +
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+ Output Cell Count +
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+ Output Frame Count +
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+ Output Cell Discard Count +
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+ Output Frame Discard Count +
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Port
VPI/VCI
Fields are the same as those of the request message.
Input Cell Count
Output Cell Count
Each gives the value of a free running 64 bit counter
counting cells arriving at the input or departing from the
output respectively. In response to a Port Statistics
message the count will be on a per port basis and in
response to a VC Statistics message the count will be on a
per VC basis.
Input Frame Count
Output Frame Count
Each gives the value of a free running 64 bit counter
counting frames (packets) arriving at the input or
departing from the output respectively. In response to a
Port Statistics message the count will be on a per port
basis and in response to a VC Statistics message the count
will be on a per VC basis.
Input Cell Discard Count
Output Cell Discard Count
Each gives the value of a free running 64 bit counter
counting cells discarded due to queue overflow on an input
port or on an output port respectively. In response to a
Port Statistics message the count will be on a per port
basis and in response to a VC Statistics message the count
will be on a per VC basis.
Input Frame Discard Count
Output Frame Discard Count
Each gives the value of a free running 64 bit counter
counting frames discarded due to queue overflow on an input
port or on an output port respectively. In response to a
Port Statistics message the count will be on a per port
basis and in response to a VC Statistics message the count
will be on a per VC basis.
HEC Error Count
Gives the value of a free running 64 bit counter counting
cells discarded due to header checksum errors on arrival at
an input port.
Invalid VPI/VCI Count
Gives the value of a free running 64 bit counter counting
cells discarded because their VPI/VCI is invalid on arrival
at an input port. An incoming VPI/VCI is invalid if no
connection is currently established having that value of
VPI/VCI.
5.2.1 Port Statistics Message
The Port Statistics message requests the statistics for the switch
port specified in the Port field. The contents of the VPI/VCI field
in the Port Statistics request message are ignored. All of the count
fields in the success response message refer to per-port counts
regardless of the virtual channels to which the cells belong. Any of
the count fields in the success response message not supported by the
port will be set to zero. The Port Statistics message is:
Message Type = 49
5.2.2 VC Statistics Message
The VC Statistics message requests the statistics for the virtual
channel specified in the VPI/VCI field that arrives on the switch
input port specified in the Port field. All of the count fields in
the success response message refer only to the specified virtual
channel. The HEC Error Count and Invalid VPI/VCI Count fields are not
VC specific and are set to zero. Any of the other count fields not
supported on a per virtual channel basis will be set to zero in the
success response message. The VC Statistics message is:
Message Type = 50
6. Configuration
The configuration messages permit the controller to discover the
capabilities of the switch. Three configuration request messages have
been defined: Switch, Port, and All Ports.
All configuration request messages have the following format:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Version | Message Type | Result | Code |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Transaction Identifier |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Port |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Port
Identifies the port number for which configuration
information is being requested. If the Port field is not
required by the message it is set to zero by the sender and
ignored by the receiver.
6.1 Switch Configuration Message
The Switch Configuration message requests the global (non port-
specific) configuration for the switch. The Switch Configuration
message is:
Message Type = 64
The Port field is not used in the request message and is set to zero.
The Switch Configuration success response message has the following
format:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Version | Message Type | Result | Code |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Transaction Identifier |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Firmware Version Number | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Switch Type | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +
| Switch Name |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Firmware Version Number
The version number of the switch control firmware
installed.
Reserved
Field is not used. It is set to zero by the sender and
ignored by the receiver.
Switch Type
A 16 bit field allocated by the manufacturer of the switch.
(For these purposes the manufacturer of the switch is
assumed to be the organization identified by the OUI in the
Switch Name field.) The Switch Type identifies the product.
When the Switch Type is combined with the OUI from the
Switch Name the product is uniquely identified. Network
Management may use this identification to obtain product
related information from a database.
Switch Name
A 48 bit quantity that is unique within the operational
context of the device. A 48 bit IEEE 802 MAC address, if
available, may be used as the Switch Name. The most
significant 24 bits of the Switch Name must be an
Organizationally Unique Identifier (OUI) that identifies
the manufacturer of the switch.
6.2 Port Configuration Message
The Port Configuration message requests the switch for the
configuration information of a single switch port. The Port field in
the request message specifies the port for which the configuration is
requested. The Port Configuration message is:
Message Type = 65.
The Port Configuration success response message has the following
format:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Version | Message Type | Result | Code |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Transaction Identifier |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Port |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Port Session Number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| zero | Min VPI | zero | Max VPI |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Min VCI | Max VCI |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Cell Rate |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Port Status | Port Type | Line Status | Priorities |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Port
The switch port to which the configuration information
refers. Configuration information relating to both the
input and the output sides of the switch port is given.
Port numbers are 32 bits wide and allocated by the switch.
The switch may choose to structure the 32 bits into sub
fields that have meaning to the physical structure of the
switch hardware (e.g. shelf, slot, interface).
Port Session Number
The current Port Session Number for the specified port.
Each switch port maintains a Port Session Number assigned
by the switch. The Port Session Number of a port remains
unchanged while the port is continuously in the Available
state. When a port returns to the Available state after it
has been Unavailable, or after a power cycle, its Port
Session Number must be changed, preferably using some form
of random number.
Min VPI
The minimum value of dynamically assigned incoming VPI that
the connection table on the input port can support and may
be controlled by GSMP.
Max VPI
The maximum value of dynamically assigned incoming VPI that
the connection table on the input port can support and may
be controlled by GSMP. It is assumed that the input port
can handle all values of VPI within the range Min VPI to
Max VPI inclusive and that GSMP may control all values
within this range. If the switch does not support virtual
paths it is acceptable for both Min VPI and Max VPI to
specify the same value, most likely zero.
Min VCI
The minimum value of dynamically assigned incoming VCI that
the connection table on the input port can support and may
be controlled by GSMP.
Max VCI
The maximum value of dynamically assigned incoming VCI that
the connection table on the input port can support and may
be controlled by GSMP. It is assumed that the input port
can handle all values of VCI within the range Min VCI to
Max VCI inclusive for each of the virtual paths in the
range Min VPI to Max VPI inclusive and that GSMP may
control all values within this range.
Cell Rate
A measure of the bandwidth of the port. It is the rate of
cells arriving at or departing from the port in cells/s. It
is assumed that both input port and output port have the
same cell rate.
Port Status
Gives the administrative state of the port. The defined
values of the Port Status field are:
Available:
Port Status = 1. The port is available to both send
and receive cells. When a port changes to the
Available state from any other administrative state,
all dynamically assigned virtual connections must be
cleared and a new Port Session Number must be
generated.
Unavailable:
Port Status = 2. The port has intentionally been taken
out of service. No cells will be transmitted from this
port. No cells will be received by this port.
Internal Loopback:
Port Status = 3. The port has intentionally been taken
out of service and is in internal loopback: cells
arriving at the output port from the switch fabric are
looped through to the input port to return to the
switch fabric. All of the ATM functions of the input
port above the PHY layer, e.g. header translation, are
performed upon the looped back cells.
External Loopback:
Port Status = 4. The port has intentionally been taken
out of service and is in external loopback: cells
arriving at the input port from the external
communications link are immediately looped back to the
communications link at the physical layer without
entering the input port. None of the ATM functions of
the input port above the PHY layer are performed upon
the looped back cells.
Bothway Loopback:
Port Status = 5. The port has intentionally been taken
out of service and is in both internal and external
loopback.
Port Type
The type of physical transmission interface for this port.
The values for this field are given by the IANAifTYPE
object from the MIB defined for the IANAifTYPE-MIB
specified in RFC1573 [rfc1573]. Example values are: SONET
or SDH (39), DS-3 (30).
Line Status
The status of the physical transmission medium connected to
the port. The defined values of the Line Status field are:
Up:
Line Status = 1. The line is able to both send and
receive cells. When the Line Status changes to Up
from either the Down or Test states, a new Port
Session Number must be generated.
Down:
Line Status = 2. The line is unable either to send or
receive cells or both.
Test:
Line Status = 3. The port or line is in a test mode,
for example, power-on test.
Priorities
The number of different priorities that this output port
can assign to virtual channel connections. Zero is invalid
in this field. If an output port is able to support "Q"
priorities, the highest priority is numbered zero and the
lowest priority is numbered "Q-1". The ability to offer
different qualities of service to different connections
based upon their priority is assumed to be a property of
the output port of the switch. It may be assumed that for
virtual channel connections that share the same output
port, an ATM cell on a connection with a higher priority is
much more likely to exit the switch before an ATM cell on a
connection with a lower priority if they are both in the
switch at the same time.
6.3 All Ports Configuration Message
The All Ports Configuration message requests the switch for the
configuration information of all of its ports. The All Ports
Configuration message is:
Message Type = 66
The Port field is not used in the request message and is set to zero.
The All Ports Configuration success response message has the
following format:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Version | Message Type | Result | Code |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Transaction Identifier |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Number of Records | Port Record Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
~ Port Records ~
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Number of Records
Field gives the number of Port Records to follow in the
message. The maximum number of port records allowed in a
single All Ports Configuration success response is 64. If a
switch has more than 64 ports it must send them in multiple
success response messages.
Port Record Length
Field gives the length of each port record in bytes. This
is currently 24 but the Port Record Length field allows for
the future definition of further fields at the end of the
port record while preserving compatibility with earlier
versions of the protocol.
Port Records follow in the remainder of the message. Each port record
has the following format:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Port |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Port Session Number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| zero | Min VPI | zero | Max VPI |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Min VCI | Max VCI |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Cell Rate |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Port Status | Port Type | Line Status | Priorities |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The definition of the fields in the port record is exactly the same
as that of the Port Configuration message.
7. Event Messages
Event messages allow the switch to inform the controller of certain
asynchronous events. Event messages are not acknowledged. The Result
field and the Code field in the message header are not used and
should be set to zero. Event messages are not sent during
initialization. Event messages have the following format:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Version | Message Type | Result | Code |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Transaction Identifier |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Port |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Port Session Number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Event Sequence Number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| zero | VPI | VCI |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Port
Field gives the switch port to which the event message
refers.
Port Session Number
The current Port Session Number for the specified port.
Event Sequence Number
The current value of the Event Sequence Number for the
specified port. The Event Sequence Number is set to zero
when the port is initialized and is incremented by one each
time an asynchronous event is detected on that port that
the switch would normally report via an Event message. The
Event Sequence Number must be incremented each time an
event occurs even if the switch is prevented from sending
an Event message due to the action of the flow control.
VPI/VCI
Field gives the VPI/VCI to which the event message refers.
If this field is not required by the event message it is
set to zero.
Each switch port must maintain an Event Sequence Number and a set of
Event Flags, one Event Flag for each type of Event message. When a
switch port sends an Event message it must set the Event Flag on that
port corresponding to the type of the event. The port is not
permitted to send another Event message of the same type until the
Event Flag has been reset. Event Flags are reset by the "Reset Event
Flags" function of the Port Management message. This is a simple flow
control preventing the switch from flooding the controller with event
messages. The Event Sequence Number of the port must be incremented
every time an event is detected on that port even if the port is
prevented from reporting the event due to the action of the flow
control. This allows the controller to detect that it has not been
informed of some events that have occurred on the port due to the
action of the flow control.
7.1 Port Up Message
The Port Up message informs the controller that the Line Status of a
port has changed from either the Down or Test state to the Up state.
When the Line Status of a switch port changes to the Up state from
either the Down or Test state a new Port Session Number must be
generated, preferably using some form of random number. The new Port
Session Number is given in the Port Session Number field. The VPI/VCI
field is not used and is set to zero. The Port Up message is:
Message Type = 80
7.2 Port Down Message
The Port Down message informs the controller that the Line Status of
a port has changed from the Up state to the Down state. This message
will be sent to report link failure if the switch is capable of
detecting link failure. The port session number that was valid before
the port went down is reported in the Port Session Number field. The
VPI/VCI field is not used and is set to zero. The Port Down message
is:
Message Type = 81
7.3 Invalid VPI/VCI Message
The Invalid VPI/VCI message is sent to inform the controller that one
or more cells have arrived at an input port with a VPI/ VCI that is
currently not allocated to an assigned connection. The input port is
indicated in the Port field, and the VPI/VCI in the VPI/VCI field.
The Invalid VPI/VCI message is:
Message Type = 82
7.4 New Port Message
The New Port message informs the controller that a new port has been
added to the switch. The port number of the new port is given in the
Port field. A new Port Session Number must be assigned, preferably
using some form of random number. The new Port Session Number is
given in the Port Session Number field. The state of the new port is
undefined so the VPI/VCI field is not used and is set to zero. The
New Port message is:
Message Type = 83
7.5 Dead Port Message
The Dead Port message informs the controller that a port has been
removed from the switch. The port number of the port is given in the
Port field. The Port Session Number that was valid before the port
was removed is reported in the Port Session Number field. The
VPI/VCI fields are not used and are set to zero. The Dead Port
message is:
Message Type = 84
8. Adjacency Protocol
The adjacency protocol is used to synchronize state across the link,
to discover the identity of the entity at the other end of a link,
and to detect when it changes. No GSMP messages other than those of
the adjacency protocol may be sent across the link until the
adjacency protocol has achieved synchronization.
8.1 Packet Format
The adjacency protocol is:
Message Type = 10
All GSMP messages belonging to the adjacency protocol have the
following structure:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Version | Message Type | Result | Code |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sender Name |
+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +
| Receiver Name |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sender Port |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Receiver Port |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sender Instance |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Receiver Instance |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Version
The GSMP protocol version number, currently Version = 1. It
should be set by the sender of the message to the GSMP
protocol version that the sender is currently running.
Result
Field is not used in the adjacency protocol. It should be
set to zero by the sender and ignored by the receiver.
Code
Field specifies the function of the message. Four Codes are
defined for the adjacency protocol:
SYN: Code = 1
SYNACK: Code = 2
ACK: Code = 3
RSTACK: Code = 4.
Sender Name
For the SYN, SYNACK, and ACK messages, is the name of the
entity sending the message. The Sender Name is a 48 bit
quantity that is unique within the operational context of
the device. A 48 bit IEEE 802 MAC address, if available,
may be used for the Sender Name. For the RSTACK message,
the Sender Name field is set to the value of the Receiver
Name field from the incoming message that caused the RSTACK
message to be generated.
Receiver Name
For the SYN, SYNACK, and ACK messages, is the name of the
entity that the sender of the message believes is at the
far end of the link. If the sender of the message does not
know the name of the entity at the far end of the link,
this field should be set to zero. For the RSTACK message,
the Receiver Name field is set to the value of the Sender
Name field from the incoming message that caused the RSTACK
message to be generated.
Sender Port
For the SYN, SYNACK, and ACK messages, is the local port
number of the link across which the message is being sent.
Port numbers are locally assigned 32 bit values. For the
RSTACK message, the Sender Port field is set to the value
of the Receiver Port field from the incoming message that
caused the RSTACK message to be generated.
Receiver Port
For the SYN, SYNACK, and ACK messages, is what the sender
believes is the local port number for the link, allocated
by the entity at the far end of the link. If the sender of
the message does not know the port number at the far end of
the link, this field should be set to zero. For the RSTACK
message, the Receiver Port field is set to the value of the
Sender Port field from the incoming message that caused the
RSTACK message to be generated.
Sender Instance
For the SYN, SYNACK, and ACK messages, is the sender's
instance number for the link. It is used to detect when the
link comes back up after going down or when the identity of
the entity at the other end of the link changes. The
instance number is a 32 bit number that is guaranteed to be
unique within the recent past and to change when the link
or node comes back up after going down. Zero is not a valid
instance number. For the RSTACK message, the Sender
Instance field is set to the value of the Receiver Instance
field from the incoming message that caused the RSTACK
message to be generated.
Receiver Instance
For the SYN, SYNACK, and ACK messages, is what the sender
believes is the current instance number for the link,
allocated by the entity at the far end of the link. If the
sender of the message does not know the current instance
number at the far end of the link, this field should be set
to zero. For the RSTACK message, the Receiver Instance
field is set to the value of the Sender Instance field from
the incoming message that caused the RSTACK message to be
generated.
8.2 Procedure
The adjacency protocol is described by the rules and state tables
given in this section.
The rules and state tables use the following operations:
o The "Update Peer Verifier" operation is defined as storing the
values of the Sender Instance, Sender Port, and Sender Name fields
from a SYN or SYNACK message received from the entity at the far
end of the link.
o The procedure "Reset the link" is defined as:
1. Generate a new instance number for the link
2. Delete the peer verifier (set to zero the values of Sender
Instance, Sender Port, and Sender Name previously stored by
the Update Peer Verifier operation)
3. Send a SYN message
4. Enter the SYNSENT state
o The state tables use the following Boolean terms and operators:
A The Sender Instance in the incoming message matches the
value stored from a previous message by the "Update Peer
Verifier" operation.
B The Sender Instance, Sender Port, and Sender Name fields in
the incoming message match the values stored from a
previous message by the "Update Peer Verifier" operation.
C The Receiver Instance, Receiver Port, and Receiver Name
fields in the incoming message match the values of the
Sender Instance, Sender Port, and Sender Name currently
sent in outgoing SYN, SYNACK, and ACK messages.
"&&" Represents the logical AND operation
"||" Represents the logical OR operation
"!" Represents the logical negation (NOT) operation.
o A timer is required for the periodic generation of SYN, SYNACK,
and ACK messages. The period of the timer is unspecified but a
value of one second is suggested.
There are two independent events: the timer expires, and a packet
arrives. The processing rules for these events are:
Timer Expires: Reset Timer
If state = SYNSENT Send SYN
If state = SYNRCVD Send SYNACK
If state = ESTAB Send ACK
Packet Arrives: If incoming message is an RSTACK
If A && C && !SYNSENT
Reset the link
Else Discard the message
Else the following State Tables.
o State synchronization across a link is considered to be achieved
when the protocol reaches the ESTAB state.
State Tables
State: SYNSENT
+======================================================================+
| Condition | Action | New State |
+====================+=====================================+===========+
| SYNACK && C | Update Peer Verifier; Send ACK | ESTAB |
+--------------------+-------------------------------------+-----------+
| SYNACK && !C | Send RSTACK | SYNSENT |
+--------------------+-------------------------------------+-----------+
| SYN | Update Peer Verifier; Send SYNACK | SYNRCVD |
+--------------------+-------------------------------------+-----------+
| ACK | Send RSTACK | SYNSENT |
+======================================================================+
State: SYNRCVD
+======================================================================+
| Condition | Action | New State |
+====================+=====================================+===========+
| SYNACK && C | Update Peer Verifier; Send ACK | ESTAB |
+--------------------+-------------------------------------+-----------+
| SYNACK && !C | Send RSTACK | SYNRCVD |
+--------------------+-------------------------------------+-----------+
| SYN | Update Peer Verifier; Send SYNACK | SYNRCVD |
+--------------------+-------------------------------------+-----------+
| ACK && B && C | Send ACK | ESTAB |
+--------------------+-------------------------------------+-----------+
| ACK && !(B && C) | Send RSTACK | SYNRCVD |
+======================================================================+
State: ESTAB
+======================================================================+
| Condition | Action | New State |
+====================+=====================================+===========+
| SYN || SYNACK | Send ACK (note 1) | ESTAB |
+--------------------+-------------------------------------+-----------+
| ACK && B && C | Send ACK (note 1) | ESTAB |
+--------------------+-------------------------------------+-----------+
| ACK && !(B && C) | Send RSTACK | ESTAB |
+======================================================================+
Note 1: No more than one ACK should be sent within any time period of
length defined by the timer.
9. Failure Response Messages
A failure response message is formed by returning the request message
that caused the failure with the Result field in the header
indicating failure (Result = 4) and the Code field giving the failure
code. The failure code specifies the reason for the switch being
unable to satisfy the request message. A failure code of 16 is used
for a failure that is specific to the particular request message and
its meaning is defined within the text describing that message. The
following failure codes are defined:
1: Unspecified reason not covered by other failure codes.
2: Invalid request message.
3: The specified request is not implemented on this switch.
4: Invalid port session number.
5: One or more of the specified ports does not exist.
6: One or more of the specified ports is down.
7: One or more of the specified VPIs or VCIs is out of range on
one or more of the requested ports.
8: The specified connection does not exist.
9: The specified branch does not exist.
10: A branch belonging to the specified multicast connection is
already established on the specified output port and the
switch cannot support more than a single branch of any
multicast connection on the same output port.
11: The limit on the maximum number of multicast connections that
the switch can support has been reached.
12: The limit on the maximum number of branches that the
specified multicast connection can support has been reached.
13: Unable to assign the requested VPI/VCI value to the requested
branch on the specified multicast connection.
14: General problem related to the manner in which multicast is
supported by the switch.
15: Out of resources (e.g. memory exhausted, etc.).
16: Failure specific to the particular message type.
REFERENCES
[I.361] "B-ISDN ATM Layer Specification," International
Telecommunication Union, ITU-T Recommendation I.361, Mar.
1993.
[I.363] "B-ISDN ATM Adaptation Layer (AAL) Specification,"
International Telecommunication Union, ITU-T Recommendation
I.363, Mar. 1993.
[rfc1700] "Assigned Numbers," STD 2, RFC1700, October 1994.
[rfc1573] "Evolution of the Interfaces Group of MIB-II," RFC1573,
January 1994.
SECURITY CONSIDERATIONS
Security issues are not discussed in this document.
AUTHORS' ADDRESSES
Peter Newman Phone: +1 (415) 846-4603
Ipsilon Networks, Inc. Email: pn@ipsilon.com
W. L. Edwards, Chief Scientist Phone: +1 (913) 534 5334
Sprint Email: texas@sprintcorp.com
Robert M. Hinden Phone: +1 (415) 846-4604
Ipsilon Networks, Inc. Email: hinden@ipsilon.com
Eric Hoffman Phone: +1 (415) 846-4610
Ipsilon Networks, Inc. Email: hoffman@ipsilon.com
Fong Ching Liaw Phone: +1 (415) 846-4607
Ipsilon Networks, Inc. Email: fong@ipsilon.com
Tom Lyon Phone: +1 (415) 846-4601
Ipsilon Networks, Inc. Email: pugs@ipsilon.com
Greg Minshall Phone: +1 (415) 846-4605
Ipsilon Networks, Inc. Email: minshall@ipsilon.com
Ipsilon Networks, Inc. is located at:
2191 East Bayshore Road
Suite 100
Palo Alto, CA 94303
USA
Sprint is located at:
Sprint
Sprint Technology Services - Long Distance Division
9300 Metcalf Avenue
Mailstop KSOPKB0802
Overland Park, KS 66212-6333
USA