(64)A.kerberos 和 PKI 都是对称密钥
B.kerberos 和 PKI 都是非对称密钥
C.kerberos 是对称密钥 ,而 PKI 是非对称密钥
D.kerberos 是非对称密钥,而 PKI 是对称密钥
(65)A.RSA
B.TGT
C.DES
D.LSA
● when the system upon which a transport entity is running fails and
subsequently reatarts,the(66)information of all active connections is lost.the
affected connections become half-open,as the side that did not fail does not yet
realize the promble.
The still active side of a half-open connections using a(67)timer.this timer
measures the time transport machine will continue to await an(68)of a transmitted
segment after the segment has been retransmitted the maximum number of times.when
the timer(69),the transport entity assumes that either the other transport entity
or the intervening network has failed.as a result,the timer closes the
connection,and signals an abnormal close to the TS user.
In the event that a transport entity fails and quickly restart,half-open
connections can be teminated more quickly by the use of the RST segment.the failed
side returns an RST I to every segment I that it receives.when the RST I reaches
the other side,it must be checked for validity dased on the (70)number I,as the RST
could be in response to an old segment .if the reset is valid,the transport entity
performs an abnormal termination.
(66)A.data
B.state
C.signal
D.control
(67)A.give-up
B.abandon
C.quit
D.connection
(68)A.reset
B.acknowledgment
C.sequence
D.synchroizer
(69)A.stops
B.restarts
C.expires
D.abandons
(70)A.sequence
B.acknowledgment
C.connection
D.message
● astute service providers realize that the continued support of legacy X.25
and asynchronous network element using separate operations network is cost(71).for
example,the maintenance of multiple networks can require additional
staff.often,this staff must be trained on multiple vendor technologies,sometimes
requiring parallel groups specializing in each(72) hence,additional maintenance
procedures must be maintained and administrative records are (73) the duplication
of trasport facilities to carry(74)network traffic is an inefficient use of
resources and,not surprisingly,more technologies installed in a central office mean
the necessity for more physical space,and an increase in power connections and power