s for TCP connection is maintained in this variable. This group also has a "tcpConnTable" connection table. This table has fields to capture the connection state, local address, local port, remote address, and remote port. The connection state is a writable field that can be changed and can take val- ues like sync, abort, listen, and closed. g. UDP Group (7) The user datagram protocol (UDP) group has a few variables and a table. Some of the variables are: udpInDatagrams: This variable keeps a count of input datagrams. udpNoPorts: The number of UDP ports at any point of time can be obtained using this variable. udpInErrors: The number of UDP error messages can be kept in this counter. udpOutDatagrams: This variable keeps a count of UDP output datagrams. The udpTable is used for collecting information on the status of UDP connection. h. EGP Group (8) The exterior gateway protocol (EGP) group has variables similar to the UDP group except that it is for the EGP protocol. Some of the variables that keep a count are egpInMsgs, egpOutMsgs, pInErrors, and egpOutErrors. i. Transmission Group (10): This group does not have any variables but is a place holder for MIB mod- ules. Some of the modules covered in the transmission group are FDDI (15), RS-232 (33), LDAP (16), X.25 (38), and SONET (39). Fundamentals of EMS, NMS and OSS/BSS CCITT Joint Standard Registration Member body Organization authority Internet Directory Management Experimental Private MIB-2 System (1) SNMP (11) Interfaces (2) AT (3) ICMP (5) UDP (7) Transmission (10) IP (4) TCP (6) EGP (8) Figure 16.3 MIB-II tree. j. SNMP Group (11) This group is for the simple network management protocol (SNMP). It has a lot of counters to capture information on the PDUs (packet data units). The various kinds of PDUs, the number of PDUs received, the number of PDUs transmitted, and the PDU errors are all captured using counters. It is also possible to enable and disable authentication traps. Being the MIB for the most popular network management pro- tocol, SNMP MIB is handle