The
snmp_atm
module implements a number of tables and scalars that enable remote access to
the ATM devices in the system. It also exports a number of
functions, that allow other modules to easily access ATM devices.
The module maintains an extension to the interface structure exported by
snmp_mibII3
for all ATM devices. This structure has the following fields:
The field points to the
snmp_mibII3
interface structure.
Fa mib
The special ATM interface MIB (see below).
Fa carrier
The current state of the carrier. One of the following:
ATMIF_CARRIER_ON
carrier detected,
ATMIF_CARRIER_OFF
no carrier,
ATMIF_CARRIER_UNKNOWN
the state of the carrier is unknown,
ATMIF_CARRIER_NONE
the device has no notion of carrier or is not able to sense it.
Fa mode
For ATM devices with a SUNI chip this is the current mode of the interface:
ATMIF_SUNI_MODE_SONET
The interface is in SONET mode.
ATMIF_SUNI_MODE_SDH
The interface is in SDH mode.
ATMIF_SUNI_MODE_UNKNOWN
The interface either has no SUNI interface or the mode is unknown (for example,
interface is down).
An ATM interface can be found by name or by SNMP interface index (see
snmp_mibII3
for a discussion of interface indexes).
The function
atm_find_if_name ();
searches an interface given a name.
The function
atm_find_if ();
searches an interface by its interface index.
Both functions return NULL if an interface cannot be found.
The ATM MIB contains the following fields:
struct atmif_mib {
u_int version; /* currently 0 */
u_int device; /* type of hardware (system specific) */
u_int serial; /* card serial number (device specific) */
u_int hw_version; /* card version (device specific) */
u_int sw_version; /* firmware version (device specific) */
u_int media; /* physical media (see MIB) */
u_char esi[6]; /* end system identifier (MAC) */
u_int pcr; /* supported peak cell rate */
u_int vpi_bits; /* number of used bits in VPI field */
u_int vci_bits; /* number of used bits in VCI field */
u_int max_vpcs; /* maximum number of VPCs */
u_int max_vccs; /* maximum number of VCCs */
};
NOTIFICATIONS
An other module can register with
to receive notifications when certain events happen on the ATM interface.
The registration is done with
atm_notify_aif ();
which takes a pointer to the interface, the calling module pointer, a callback
function and a user argument that is passed to the callback function.
The callback function is called with the interface pointer, a notification
code, a notification argument and the user argument. The following
notifications are defined:
ATMIF_NOTIFY_DESTROY
The interface is destroyed. The notification argument is not used.
ATMIF_NOTIFY_CARRIER
The carrier state on the interface has changed. The argument is the
old
state of the carrier. The new state can be obtained from the interface
structure.
ATMIF_NOTIFY_VCC
A permanent VCC has been created or destroyed. The argument is an u_int that
can be decoded as follows:
state
is 0 if the VCC was destroyed and 1 if it was created.
The registration for notification can be undone by passing the return
value from
atm_notify_aif ();
to
atm_unnotify_aif (.);
The registrations is automatically removed if the interface is destroyed.
MIB
The MIB implemented by the module is defined in
BEGEMOT-ATM.txt
In the generic part there are two tables and one scalar, there is also
a system specific group:
begemotAtmIfTable
This table is an extension of
ifTable
It contains a row for each ATM interface and is index with
ifIndex
All fields are read-only except the
begemotAtmIfMode
column.
begemotAtmIfTableLastChange
Contains the tick when a row was created or destroyed in the above table or
0, if the table did not change since start of the SNMP agent.
begemotAtmHWTable
Is also indexed by
ifIndex
and contains hardware specific information. This table is read-only.
FILES
/usr/share/snmp/defs/atm_tree.def
The description of the MIB tree implemented by
.
/usr/share/snmp/mibs/BEGEMOT-ATM.txt
This is the MIB that is implemented by this module.
