Frame Relay is simplified form of (1) , similar in principle to (2) , in which synchronous, frames of data are routed to different destinations depending on header information.
Packets are routed throught one or more Virtual Circuits known as (3) Most Virtual Circuits are (4) , which means that the network provider sets up all DLCI connections at subscription time. (5) are also part of the Frame Relay specification. They privide a link that only lasts only as long as the session.

1（）

A:Datagram Switching B:Datagram Routing C:Packet Switchig D:packet Routing

Frame Relay is simplified form of (66) , similar in principle to (67) , in which synchronous, frames of data are routed to different destinations depending on header information.
Packets are routed throught one or more Virtual Circuits known as (68) . Most Virtual Circuits are (69) , which means that the network provider sets up all DLCI connections at subscription time. (70) are also part of the Frame Relay specification. They privide a link that only lasts only as long as the session.

66（）

A:Datagram Switching B:Datagram Routing C:Packet Switching D:packet Routing

Frame Relay is simplified form of （） ,similar in principle to （） , in which synchronous, frames of data are routed to different destinations depending on header information. Packets are routed throught one or more Virtual Circuits known as （） . Most Virtual Circuits are （） ,which means that the network provider sets up all DLCI connections at subscription time. （） are also part of the Frame Relay specification. They privide a link that only lasts only as long as the session.

Frame Relay is simplified form of （）

A:Datagram Switching B:Datagram Routing C:Packet Switching D:Packet Routing

One of the main responsibilities of ICMP is to report ______. Although technology has produced increasingly reliable transmission media, errors still exist and must be handled. IP is an ______ protocol. This means that error checking and error control are not a concem ofIP JCMP wasdesigned, in part, to compensate for this shortcoming. Howerver, ICMP does not ______ errors, itsimply reports them. Error correction is left to the higher-level protocols. Error messages arealways sent to the original ______ because the only information available in the datagram aboutthe route is the source and destination 1P addresses. ICMP uses the source IP address to send theerror massage to the source of the ______.

A:datagram B:frame C:service D:Protocol

One ofthe main resposibilities of ICMP is to report(1).Although technology has produced increasingly relaible transmission media, errors still exist and must be handled. IP is an (2) protocol. This means that error checking and error control are not a concern of IP. ICMP was designed, in part, to compensate for this shortcoming. Howerver, ICMP does not (3) errors, it simply report them. Error correction is left to the higher-level potocols. Error messages are always sent to the original (4) because the only information available in the datagram about the route is the source and destination IP addresses. ICMP use the source IP address to sent the error massage to the source of the (5).

空白（5）处应选择（）

A:datagram B:frame C:service D:protocol

One ofthe main resposibilities ofICMP is to report  （） . Although technology hasproduced increasingly relaible transmission media, errors still exist and must be handled. IP isan  （）  protocol. This means that error checking and error control are not a concem ofIP. ICMP was designed, in part, to compensate for this shortcoming. Howerver, ICMP doesnot  （） errors, it simply report them. Error correction is left to the higher-levelpotocols. Error messages are always sent to the original  （）  because the only informationavailable in the datagram about the route is the source and destination IP addresses. ICMP usethe source IP address to sent the error massage to the source ofthe（）.

ICMP usethe source IP address to sent the error massage to the source ofthe（）.

A:datagram B:frame C:service D:protocol

●One of the main resposibilities of ICMP is to report（）.Although technology has produced increasingly reliable transmission media, errors still exist and must be handled．IP is an （） protocol．This means that error checking and error control are not a concern of IP．ICMP was designed，in part，to compensate for this shortcoming．Howerver, ICMP does not（） errors，it simply reports them．Error correction is left to the higher-level potocols．Error messages are always sent to the original （） because the only information available in the datagram about the route is the source and destination IP addresses．ICMP uses the source IP address to send the error massage to the source of the （） .

ICMP uses the source IP address to send the error massage to the source of the（）

A:datagram B:frame C:service D:protocol

●One of the main resposibilities of ICMP is to report（）.Although technology has produced increasingly reliable transmission media, errors still exist and must be handled．IP is an （） protocol．This means that error checking and error control are not a concern of IP．ICMP was designed，in part，to compensate for this shortcoming．Howerver, ICMP does not（） errors，it simply reports them．Error correction is left to the higher-level potocols．Error messages are always sent to the original （） because the only information available in the datagram about the route is the source and destination IP addresses．ICMP uses the source IP address to send the error massage to the source of the （） .

ICMP uses the source IP address to send the error massage to the source of the（）

A:datagram B:frame C:service D:protocol