be returned indicating: "Only point-to-point bidirectional
connections may be established."
It should be noted that different switches support multicast in
different ways. There will be a limit to the total number of point-
to-multipoint connections any switch can support, and possibly a
limit on the maximum number of branches that a point-to-multipoint
connection may specify. Some switches also impose a limit on the
number of different VPI/VCI values that may be assigned to the output
branches of a point-to-multipoint connection. Many switches are
incapable of supporting more than a single branch of any particular
point-to-multipoint connection on the same output port. Specific
failure codes are defined for some of these conditions.
4.2 Delete Tree Message
The Delete Tree message is a connection management message used to
delete an entire virtual channel connection or an entire virtual path
connection. All remaining branches of the connection are deleted. A
virtual channel connection is specified by the Input Port, Input VPI,
and Input VCI fields. A virtual path connection is specified by the
Input Port and Input VPI fields. The Output Port, Output VPI, and
Output VCI fields are not used in this message. The Delete Tree
message is:
Message Type = 18
If the Result field of the request message is "AckAll" a success
response message must be sent upon successful deletion of the
specified connection. The success message must not be sent until the
delete operation has been completed and if possible, not until all
data on the connection, queued for transmission, has been
transmitted. The Number of Branches field is not used in either the
request or response messages of the Delete Tree message.
4.3 Verify Tree Message
The Verify Tree message has been removed from this version of GSMP.
Its function has been replaced by the Number of Branches field in the
success response to the Add Branch message which contains the number
of branches on a virtual channel connection after successful
completion of an add branch operation.
Message Type = 19 is reserved.
If a request message is received with Message Type = 19 a failure
response must be returned with the Code field indicating: "The
specified request is not implemented in this version of the
protocol."
4.4 Delete All Message
The Delete All message is a connection management message used to
delete all connections on a switch input port. All connections that
arrive at the specified input port must be deleted. On completion of
the operation all dynamically assigned VPI/VCI values for the
specified port must be unassigned, i.e. there must be no virtual
connections established in the VPI/VCI space that GSMP controls on
this port. The Input VPI, Input VCI, Output Port, Output VPI, and
Output VCI fields are not used in this message. The Delete All
message is:
Message Type = 20
If the Result field of the request message is "AckAll" a success
response message must be sent upon completion of the operation. The
Number of Branches field is not used in either the request or
response messages of the Delete All message. The success response
message must not be sent until the operation has been completed.
The following failure response messages may be returned to a Delete
All request.
The specified request is not implemented on this switch.
One or more of the specified ports does not exist.
Invalid Port Session Number.
If any field in a Delete All message not covered by the above failure
codes is invalid, a failure response must be returned indicating:
"Invalid request message." Else, the delete all operation must be
completed successfully and a success message returned. No other
failure messages are permitted.
4.5 Delete Branches Message
The Delete Branches message is a connection management message used
to request one or more delete branch operations. Each delete branch
operation deletes a branch of a virtual channel connection or a
virtual path connection, or in the case of the last branch of a
connection, it deletes the connection. The Delete Branches message
is:
Message Type = 17
The request 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 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Reserved | Number of Elements |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
~ Delete Branch Elements ~
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Number of Elements
Specifies the number of Delete Branch Elements to follow in
the message. The number of Delete Branch Elements in a
Delete Branches message must not cause the packet length to
exceed the maximum transmission unit defined by the
encapsulation.
Each Delete Branch Element specifies an output branch to be deleted
and has the following structure:
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Port Session Number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Input Port |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Error | Input VPI | Input VCI |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Output Port |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|x x x x| Output VPI | Output VCI |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Error
Is used to return a failure code indicating the reason for
the failure of a specific Delete Branch Element in a Delete
Branches failure response message. The Error field is not
used in the request message and must be set to zero. A
value of zero is used to indicate that the delete operation
specified by this Delete Branch Element was successful.
Values for the other failure codes are specified in Section
3.2, "Failure Response Messages."
All other fields of the Delete Branch Element have the same
definition as specified for the other connection management
messages.
In each Delete Branch Element, either a virtual channel connection is
specified by the Input Port, Input VPI, and Input VCI fields; or a
virtual path connection is specified by the Input Port and Input VPI
fields. The specific branch to be deleted is indicated by the Output
Port, Output VPI, and Output VCI fields for virtual channel
connections and by the Output Port and Output VPI for virtual path
connections.
If the Result field of the Delete Branches request message is
"AckAll" a success response message must be sent upon successful
deletion of the branches specified by all of the Delete Branch
Elements. The success response message must not be sent until all of
the delete branch operations have been completed. The success
response message is only sent if all of the requested delete branch
operations were successful. No Delete Branch Elements are returned in
a Delete Branches success response message and the Number of Elements
field must be set to zero.
If there is a failure in any of the Delete Branch Elements a Delete
Branches failure response message must be returned. The Delete
Branches failure response message is a copy of the request message
with the Code field of the entire message set to, "Failure specific
to the particular message type," and the Error field of each Delete
Branch Element indicating the result of each requested delete
operation. A failure in any of the Delete Branch Elements must not
interfere with the processing of any other Delete Branch Elements.
4.6 Move Branch Message
The Move Branch message is used to move a branch of an existing
connection from its current output port VPI/VCI to a new output port
VPI/VCI in a single atomic transaction. This operation occurs
frequently in IP switching, every time a flow is switched from hop-
by-hop forwarding to a dedicated virtual channel. The Move Branch
connection management message has the following format for both
request and response messages:
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 Session Number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Input Port |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Flags | Input VPI | Input VCI |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Old Output Port |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|x x x x| Old Output VPI | Old Output VCI |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| New Output Port |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|x x x x| New Output VPI | New Output VCI |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Number of Branches | Class of Service |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The VCC Move Branch message is a connection management message used
to move a single output branch of a virtual channel connection from
its current output port, output VPI, and output VCI, to a new output
port, output VPI, and output VCI on the same virtual channel
connection. None of the other output branches are modified. When the
operation is complete the original output VPI/VCI on the original
output port will be deleted from the connection. The VCC Move Branch
message is:
Message Type = 22
For the VCC Move Branch message, if the virtual channel connection
specified by the Input Port, Input VPI, and Input VCI fields already
exists, and the output branch specified by the Old Output Port, Old
Output VPI, and Old Output VCI fields exists as a branch on that
connection, the output branch specified by the New Output Port, New
Output VPI, and New Output VCI fields is added to the connection and
the branch specified by the Old Output Port, Old Output VPI, and Old
Output VCI fields is deleted. If the Result field of the request
message is "AckAll" a success response message must be sent upon
successful completion of the operation. The success response message
must not be sent until the Move Branch operation has been completed.
For the VCC Move Branch message, if the virtual channel connection
specified by the Input Port, Input VPI, and Input VCI fields already
exists, but the output branch specified by the Old Output Port, Old
Output VPI, and Old Output VCI fields does not exist as a branch on
that connection, a failure response must be returned with the Code
field indicating, "The specified branch does not exist."
The VPC Move Branch message is a connection management message used
to move a single output branch of a virtual path connection from its
current output port and output VPI, to a new output port and output
VPI on the same virtual channel connection. None of the other output
branches are modified. When the operation is complete the original
output VPI on the original output port will be deleted from the
connection. The VPC Move Branch message is:
Message Type = 27
For the VPC Move Branch message, if the virtual path connection
specified by the Input Port and Input VPI fields already exists, and
the output branch specified by the Old Output Port and Old Output VPI
fields exists as a branch on that connection, the output branch
specified by the New Output Port and New Output VPI fields is added
to the connection and the branch specified by the Old Output Port and
Old Output VPI fields is deleted. If the Result field of the request
message is "AckAll" a success response message must be sent upon
successful completion of the operation. The success response message
must not be sent until the Move Branch operation has been completed.
For the VPC Move Branch message, if the virtual path connection
specified by the Input Port and Input VPI fields already exists, but
the output branch specified by the Old Output Port and Old Output VPI
fields does not exist as a branch on that connection, a failure
response must be returned with the Code field indicating, "The
specified branch does not exist."
If the virtual channel connection specified by the Input Port, Input
VPI, and Input VCI fields; or the virtual path connection specified
by the Input Port and Input VPI fields; does not exist, a failure
response must be returned with the Code field indicating, "The
specified connection does not exist."
If the output branch specified by the New Output Port, New Output
VPI, and New Output VCI fields for a virtual channel connection; or
the output branch specified by the New Output Port and New Output VPI
fields for a virtual path connection; is already in use by any
connection other than that specified by the Input Port, Input VPI,
and Input VCI fields then the resulting output branch will have
multiple input branches. If multiple point-to-point connections share
the same output branch the result will be a multipoint-to-point
connection. If multiple point-to-multipoint trees share the same
output branches the result will be a multipoint-to-multipoint
connection.
5. Port Management Messages
5.1 Port Management Message
The Port Management message allows a port to be brought into service,
taken out of service, looped back, reset, or the transmit cell rate
changed. Only the Bring Up and the Reset Input Port functions change
the connection state (established connections) on the input port.
Only the Bring Up function changes the value of the Port Session
Number. If the Result field of the request message is "AckAll" a
success response message must be sent upon successful completion of
the operation. The success response message must not be sent until
the operation has been completed. The Port Management Message is:
Message Type = 32
The Port Management message has the following format for the request
and success response messages:
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 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Event Flags | Duration | Function |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Transmit Cell Rate |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Event Sequence Number
In the success response message gives the current value of
the Event Sequence Number of the switch port indicated by
the Port field. The Event Sequence Number is set to zero
when the port is initialized. It is incremented by one each
time the port detects an asynchronous event that the switch
would normally report via an Event message. If the Event
Sequence Number in the success response differs from the
Event Sequence Number of the most recent Event message
received for that port, events have occurred that were not
reported via an Event message. This is most likely to be
due to the flow control that restricts the rate at which a
switch can send Event messages for each port. In the
request message this field is not used.
Event Flags
Field in the request message is used to reset the Event
Flags in the switch port indicated by the Port field. Each
Event Flag in a switch port corresponds to a type of Event
message. When a switch port sends an Event message it sets
the corresponding Event Flag on that port. The port is not
permitted to send another Event message of the same type
until the Event Flag has been reset. If the Function field
in the request message is set to "Reset Event Flags," for
each bit that is set in the Event Flags field, the
corresponding Event Flag in the switch port is reset.
The Event Flags field is only used in a request message
with the Function field set to "Reset Event Flags." For all
other values of the Function field, the Event Flags field
is not used. In the success response message the Event
Flags field must be set to the current value of the Event
Flags for the port, after the completion of the operation
specified by the request message, for all values of the
Function field. Setting the Event Flags field to all zeros
in a "Reset Event Flags" request message allows the
controller to obtain the current state of the Event Flags
and the current Event Sequence Number of the port without
changing the state of the Event Flags.
The correspondence between the types of Event message and
the bits of the Event Flags field is as follows:
0 1 2 3 4 5 6 7
+-+-+-+-+-+-+-+-+
|U|D|I|N|Z|x x x|
+-+-+-+-+-+-+-+-+
U: Port Up Bit 0, (most significant bit)
D: Port Down Bit 1,
I: Invalid VPI/VCI Bit 2,
N: New Port Bit 3,
Z: Dead Port Bit 4,
x: Unused Bits 5--7.
Duration
Is the length of time, in seconds, that any of the loopback
states remain in operation. When the duration has expired
the port will automatically be returned to service. If
another Port Management message is received for the same
port before the duration has expired, the loopback will
continue to remain in operation for the length of time
specified by the Duration field in the new message. The
Duration field is only used in request messages with the
Function field set to Internal Loopback, External Loopback,
or Bothway Loopback.
Function
Specifies the action to be taken. The specified action will
be taken regardless of the current status of the port
(Available, Unavailable, or any Loopback state). If the
specified function requires a new Port Session Number to be
generated, the new Port Session Number must be returned in
the success response message. The defined values of the
Function field are:
Bring Up:
Function = 1. Bring the port into service. All
connections that arrive at the specified input port
must be deleted and a new Port Session Number must be
selected using some form of random number. On
completion of the operation all dynamically assigned
VPI/VCI values for the specified input port must be
unassigned, i.e. no virtual connections will be
established in the VPI/VCI space that GSMP controls on
this input port. The Port Status of the port
afterwards will be Available.
Take Down:
Function = 2. Take the port out of service. Any cells
received at this port will be discarded. No cells will
be transmitted from this port. The Port Status of the
port afterwards will be Unavailable.
The behavior is undefined if the port is taken down
over which the GSMP session that controls the switch
is running. (In this case the most probable behavior
would be for the switch either to ignore the message
or to terminate the current GSMP session and to
initiate another session, possibly with the backup
controller, if any.) The correct method to reset the
link over which GSMP is running is to issue an RSTACK
message in the adjacency protocol.
Internal Loopback:
Function = 3. 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 physical layer,
e.g. header translation, are performed upon the looped
back cells. The Port Status of the port afterwards
will be Internal Loopback.
External Loopback:
Function = 4. 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 physical layer
are performed upon the looped back cells. The Port
Status of the port afterwards will be External
Loopback.
Bothway Loopback:
Function = 5. Both internal and external loopback are
performed. The Port Status of the port afterwards will
be Bothway Loopback.
Reset Input Port:
Function = 6. All connections that arrive at the
specified input port must be deleted and the input and
output port hardware re-initialized. On completion of
the operation all dynamically assigned VPI/VCI values
for the specified input port must be unassigned, i.e.
no virtual connections will be established in the
VPI/VCI space that GSMP controls on this input port.
The range of VPIs and VCIs that may be controlled by
GSMP on this port will be set to the default values
specified in the Port Configuration message. The
transmit cell rate of the output port must be set to
its default value. The Port Session Number is not
changed by the Reset Input Port function. The Port
Status of the port afterwards will be Unavailable.
Reset Event Flags:
Function = 7. For each bit that is set in the Event
Flags field, the corresponding Event Flag in the
switch port must be reset. The Port Status of the port
is not changed by this function.
Set Transmit Cell Rate:
Function = 8. Sets the transmit cell rate of the
output port as close as possible to the rate specified
in the Transmit Cell Rate field. In the success
response message the Transmit Cell Rate must indicate
the actual transmit cell rate of the output port. If
the transmit cell rate of the requested output port
cannot be changed, a failure response must be returned
with the Code field indicating: "The transmit cell
rate of this output port cannot be changed." If the
transmit cell rate of the requested output port can be
changed, but the value of the Transmit Cell Rate field
is beyond the range of acceptable values, a failure
response must be returned with the Code field
indicating: "Requested transmit cell rate out of range
for this output port." In the failure response message
the Transmit Cell Rate must contain the same value as
contained in the request message that caused the
failure. The transmit cell rate of the output port is
not changed by the Bring Up, Take Down, or any of the
Loopback functions. It is returned to the default
value by the Reset Input Port function.
Transmit Cell Rate
This field is only used in request and success response
messages with the Function field set to "Set Transmit Cell
Rate." It is used to set the output cell rate of the output
port. It is specified in cells/s. If the Transmit Cell Rate
field contains the value 0xFFFFFFFF the transmit cell rate
of the output port should be set to the highest valid
value.
5.2. Label Range Message
The default label range, Min VPI to Max VPI and Min VCI to Max VCI,
is specified for each port by the Port Configuration or the All Ports
Configuration messages. When the protocol is initialized, before the
transmission of any Label Range messages, the label range of each
port will be set to the default label range. (The default label range
is dependent upon the switch design and configuration and is not
specified by the GSMP protocol.) The Label Range message allows the
range of VPIs supported by a specified port, or the range of VCIs
supported by a specified VPI on a specified port, to be changed.
Each switch port must declare whether it supports the Label Range
message in the Port Configuration or the All Ports Configuration
messages. The Label Range message is:
Message Type = 33
The Label Range message has the following format for the request and
success response messages:
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 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|Q|V|x x| Min VPI |x x x x| Max VPI |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Min VCI | Max VCI |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Remaining VPIs | Remaining VCIs |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Flags
Q: Query
If the Query flag is set in a request message, the switch
must respond with the current range of valid VPIs, or the
current range of valid VCIs on a specified VPI, according
to the VPI/VCI flag. The current label range is not changed
by a request message with the Query flag set. If the Query
flag is zero, the message is requesting a label change
operation.
V: VPI/VCI
If the VPI/VCI flag is set, the message refers to a range
of VPIs only. The Min VCI and Max VCI fields are unused. If
the VPI/VCI flag is zero the message refers to a range of
VCIs on either one VPI or on a range of VPIs.
x: Unused
Min VPI
Max VPI
Specify a range of VPI values, Min VPI to Max VPI
inclusive. A single VPI may be specified with a Min VPI
and a Max VPI having the same value. In a request message,
if the value of the Max VPI field is less than or equal to
the value of the Min VPI field, the requested range is a
single VPI with a value equal to the Min VPI field. Zero is
a valid value. In a request message, if the Query flag is
set, and the VPI/VCI flag is zero, the Max VPI field
specifies a single VPI and the Min VPI field is not used.
The maximum valid value of these fields for both request
and response messages is 0xFFF.
Min VCI
Max VCI
Specify a range of VCI values, Min VCI to Max VCI
inclusive. A single VCI may be specified with a Min VCI
and a Max VCI having the same value. In a request message,
if the value of the Max VCI field is less than or equal to
the value of the Min VCI field, the requested range is a
single VCI with a value equal to the Min VCI field. Zero is
a valid value. (However, VPI=0, VCI=0 is not available as
a virtual channel connection as it is used as a special
value in ATM to indicate an unassigned cell.)
Remaining VPIs
Remaining VCIs
These fields are unused in the request message. In the
success response message and in the failure response
message these fields give the maximum number of remaining
VPIs and VCIs that could be requested for allocation on the
specified port (after completion of the requested operation
in the case of the success response). It gives the switch
controller an idea of how many VPIs and VCIs it could
request. The number given is the maximum possible given the
constraints of the switch hardware. There is no implication
that this number of VPIs and VCIs is available to every
switch port.
If the Query flag and the VPI/VCI flag are set in the request
message, the switch must reply with a success response message
containing the current range of valid VPIs that are supported by the
port. The Min VPI and Max VPI fields are not used in the request
message.
If the Query flag is set and the VPI/VCI flag is zero in the request
message, the switch must reply with a success response message
containing the current range of valid VCIs that are supported by the
VPI specified by the Max VPI field. If the requested VPI is invalid,
a failure response must be returned indicating: "One or more of the
specified input VPIs is invalid." The Min VPI field is not used in
either the request or success response messages.
If the Query flag is zero and the VPI/VCI flag is set in the request
message, the Min VPI and Max VPI fields specify the new range of VPIs
to be allocated to the input port specified by the Port field.
Whatever the range of VPIs previously allocated to this port it
should be increased or decreased to the specified value.
If the Query flag and the VPI/VCI flag are zero in the request
message, the Min VCI and Max VCI fields specify the range of VCIs to
be allocated to each of the VPIs specified by the VPI range.
Whatever the range of VCIs previously allocated to each of the VPIs
within the specified VPI range on this port, it should be increased
or decreased to the specified value. The allocated VCI range must be
the same on each of the VPIs within the specified VPI range.
The success response to a Label Range message requesting a change of
label range is a copy of the request message with the Remaining VPIs
and Remaining VCIs fields updated to the new values after the Label
Range operation.
If the switch is unable to satisfy a request to change the VPI range,
it must return a failure response message with the Code field set to
"Cannot support requested VPI range." In this failure response
message the switch must use the Min VPI and Max VPI fields to suggest
a VPI range that it would be able to satisfy.
If the switch is unable to satisfy a request to change the VCI range
on all VPIs within the requested VPI range, it must return a failure
response message with the Code field set to "Cannot support requested
VCI range on all requested VPIs." In this failure response message
the switch must use the Min VPI, Max VPI, Min VCI, and Max VCI fields
to suggest a VPI and VCI range that it would be able to satisfy.
In all other failure response messages for the label range operation
the switch must return the values of Min VPI, Max VPI, Min VCI, and
Max VCI from the request message.
While switches can typically support all 256 or 4096 VPIs the VCI
range that can be supported is often more constrained. Often the Min
VCI must be 0 or 32. Typically all VCIs within a particular VPI must
be contiguous. The hint in the failure response message allows the
switch to suggest a label range that it could satisfy in view of its
particular architecture.
While the Label Range message is defined to specify both a range of
VPIs and a range of VCIs within each VPI, the most likely use is to
change either the VPI range or the range of VCIs within a single VPI.
It is possible for a VPI to be valid but to be allocated no valid
VCIs. Such a VPI could be used for a virtual path connection but to
support virtual channel connections it would need to be allocated a
range of VCIs.
A Label Range request message may be issued regardless of the Port
Status or the Line Status of the target switch port. If the Port
field of the request message contains an invalid port (a port that
does not exist or a port that has been removed from the switch) a
failure response message must be returned with the Code field set to,
"One or more of the specified ports does not exist."
6. State and Statistics Messages
The state and statistics messages permit the controller to request
the values of various hardware counters associated with the switch
input and output ports, virtual path connections, virtual channel
connections, and QoS Classes. They also permit the controller to
request the connection state of a switch input port. The Connection
Activity message is used to determine whether one or more specific
virtual channel connections or virtual path connections have recently
been carrying traffic. The Statistics message is used to query the
various port, connection, and QoS class traffic and error counters.
The Report Connection State message is used to request an input port
to report the connection state for a single virtual channel
connection, a single virtual path connection, or for the entire input
port.
6.1 Connection Activity Message
The Connection Activity message is used to determine whether one or
more specific virtual channel connections or virtual path connections
have recently been carrying traffic. The Connection Activity message
contains one or more Activity Records. Each Activity Record is used
to request and return activity information concerning a single
virtual channel connection or virtual path connection. Each virtual
channel connection is specified by its input port, input VPI, and
input VCI. Each virtual path connection is specified by its input
port and input VPI. These are specified in the Input Port, Input VPI,
and Input VCI fields of each Activity Record. Two forms of activity
detection are supported. If the switch supports per connection
traffic accounting, the current value of the traffic counter for each
specified virtual channel connection or virtual path connection must
be returned. The units of traffic counted are not specified but will
typically be either cells or frames. The controller must compare the
traffic counts returned in the message with previous values for each
of the specified connections to determine whether each connection has
been active in the intervening period. If the switch does not
support per connection traffic accounting, but is capable of
detecting per connection activity by some other unspecified means,
the result may be indicated for each connection using the Flags
field. The Connection Activity message is:
Message Type = 48
The Connection Activity request and success response 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 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Number of Records | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
~ Activity Records ~
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Number of Records
Field specifies the number of Activity Records to follow.
The number of Connection Activity records in a single
Connection Activity message must not cause the packet
length to exceed the maximum transmission unit defined by
the encapsulation.
Each Activity Record has the following format:
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Input Port |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|V|C|A|x| Input VPI | Input VCI |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+ Traffic Count +
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Input Port
Identifies the port number of the input port on which the
connection of interest arrives in order to identify the
connection (regardless of whether the traffic count for the
connection is maintained on the input port or the output
port).
Input VPI
Input VCI
Fields identify the specific virtual path connection or
virtual channel connection for which statistics are being
requested. For a virtual path connection the Input VCI
field is not used.
Flags
V: Valid Record
In the success response message the Valid Record flag is
used to indicate an invalid Activity Record. The flag must
be zero if any of the fields in this Activity Record are
invalid, if the input port specified by the Input Port
field does not exist, or if the specified connection does
not exist. If the Valid Record flag is zero in a success
response message, the Counter flag, the Activity flag, and
the VC Traffic Count field are undefined. If the Valid
Record flag is set, the Activity Record is valid, and the
Counter and Activity flags are valid. The Valid Record flag
is not used in the request message.
C: Counter
In a success response message, if the Valid Record flag is
set, the Counter flag, if zero, indicates that the value in
the VC Traffic Count field is valid. If set, it indicates
that the value in the Activity flag is valid. The Counter
flag is not used in the request message.
A: Activity
In a success response message, if the Valid Record and
Counter flags are set, the Activity flag, if set, indicates
that there has been some activity on this connection since
the last Connection Activity message for this connection.
If zero, it indicates that there has been no activity on
this connection since the last Connection Activity message
for this connection. The Activity flag is not used in the
request message.
x: Unused
Traffic Count
Field is not used in the request message. In the success
response message, if the switch supports per connection
traffic counting, the Traffic Count field must be set to
the value of a free running, connection specific, 64-bit
traffic counter counting traffic flowing across the
specified connection. The value of the traffic counter is
not modified by reading it. If per connection traffic
counting is supported, the switch must report the
Connection Activity result using the traffic count rather
than using the Activity flag.
The format of the failure response is the same as the request message
with the Number of Records field set to zero and no VC Activity
records returned in the message. If the switch is incapable of
detecting per connection activity, a failure response must be
returned indicating, "The specified request is not implemented on
this switch."
6.2 Statistics Messages
The Statistics messages are used to query the various port,
connection, and QoS class traffic and error counters.
The Statistics 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 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| zero | VPI | VCI |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| QoS Class Identifier |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
VPI
VCI
Fields identify the specific virtual path connection or
virtual channel connection for which statistics are being
requested. For a virtual path connection the Input VCI
field is not used. For requests that do not require a
virtual path connection or virtual channel connection to be
specified, the VPI and VCI fields are not used.
QoS Class Identifier
Field identifies the QoS class for which statistics are
being requested. This field is only used if the QoS Class
Establishment message defined in section 9.4 is
implemented.
The success response for the Statistics 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 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| zero | VPI | VCI |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| QoS Class Identifier |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+ 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
QoS Class Identifier
Fields are the same as those of the request message.
Input Cell Count
Output Cell Count
Give the value of a free running 64-bit counter counting
cells arriving at the input or departing from the output
respectively.
Input Frame Count
Output Frame Count
Give the value of a free running 64-bit counter counting
frames (packets) arriving at the input or departing from
the output respectively.
Input Cell Discard Count
Output Cell Discard Count
Give 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.
Input Frame Discard Count
Output Frame Discard Count
Give the value of a free running 64-bit counter counting
frames discarded due to congestion on an input port or on
an output port respectively.
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. For a virtual channel connection an
incoming VPI/VCI is invalid if no connection is currently
established having that value of VPI/VCI. For a virtual
path connection an incoming VPI is invalid if no connection
is currently established having that value of VPI.
6.2.1 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 and the
QoS Class Identifier fields 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 connection or QoS class to
which the cells belong. Any of the count fields in the success
response message not supported by the port must be set to zero. The
Port Statistics message is:
Message Type = 49
6.2.2 Connection Statistics Message
The Connection Statistics message requests the statistics for the
virtual channel connection specified in the VPI/VCI field, or the
virtual path connection specified in the VPI field, that arrives on
the switch input port specified in the Port field, regardless of the
QoS class to which the cells belong. All of the count fields in the
success response message refer only to the specified connection. The
HEC Error Count and Invalid VPI/VCI Count fields are not connection
specific and must be set to zero. Any of the other count fields not
supported on a per connection basis must be set to zero in the
success response message. The Connection Statistics message is:
Message Type = 50
6.2.3 QoS Class Statistics Message
The QoS Class Statistics message requests the statistics for the QoS
class specified by the QoS Class Identifier field that arrives on the
switch input port specified in the Port field, regardless of the
connection to which the cells belong. The QoS Statistics message is
only used if the QoS Class Establishment message defined in section
9.4 is implemented. The contents of the VPI/VCI fields in the QoS
Class Statistics request message are ignored. All of the count fields
in the success response message refer only to the specified QoS
class. The HEC Error Count and Invalid VPI/VCI Count fields are not
specific to a QoS class and must be set to zero. Any of the other
count fields not supported on a per QoS class basis must be set to
zero in the success response message. The QoS Class Statistics
message is:
Message Type = 51
6.3 Report Connection State Message
The Report Connection State message is used to request an input port
to report the connection state for a single virtual channel
connection, a single virtual path connection, or for the entire input
port. The Report Connection State message is:
Message Type = 52
The Report Connection State request 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 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Input Port |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|A|V|x x| Input VPI | Input VCI |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Input Port
Identifies the port number of the input port for which the
connection state is being requested.
Flags
A: All Connections
If the All Connections flag is set, the message requests
the connection state for all virtual path connections and
virtual channel connections that arrive at the input port
specified by the Input Port field. In this case the Input
VPI and Input VCI fields and the VPI/VCI flag are unused.
V: VPI/VCI
If the All Connections flag is zero and the VPI/VCI flag is
set, the message requests the connection state for the
virtual path connection that arrives at the input port
specified by the Input Port and Input VPI fields. If the
specified Input VPI identifies a virtual path connection
(i.e. a single switched virtual path) the state for that
connection is requested. If the specified Input VPI
identifies a virtual path containing virtual channel
connections, the message requests the connection state for
all virtual channel connections that belong to the
specified virtual path. The Input VCI field is not used.
If the All Connections flag is zero and the VPI/VCI flag is
also zero, the message requests the connection state for
the virtual channel connection that arrives at the input
port specified by the Port, Input VPI and Input VCI fields.
x: Unused.
Input VPI
Input VCI
Fields identify the specific virtual path connection, the
specific virtual path, or the specific virtual channel
connection for which connection state is being requested.
For a virtual path connection (switched as a single virtual
path connection) or a virtual path (switched as one or more
virtual channel connections within the virtual path) the
Input VCI field is not used. For requests that do not
require a virtual path connection or virtual channel
connection to be specified, the Input VPI and Input VCI
fields are not used.
The Report Connection State 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 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Input Port |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sequence Number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
~ Connection Records ~
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Input Port
Is the same as the Input Port field in the request message.