Which two Internet Protocol (IP) telephony devices are best categorized as infrastructurecomponents?（）
The Internet is based on connectionless end-to-end packet service, which traditionally provided best-effort means of data （请作答此空）using the Transmission Control Protocol/Internet Protocol Suite. Although the （ ）design gives the Internet its flexibility and robustness, its packet dynamics also make it prone to congestion problems,especially at （ ）that connect networks of widely different bandwidths.The initial QoS function set was for internet hosts.One major problem with expensive wide-area（ ）links is the excessive overhead due to small Transmission Control Protocol packets created by applications such as telnet and rlogin. The Nagle （ ），which solves this issue,is now supported by all IP host implementations.A.transformation B.transportation C.processing D.progressing
点击查看答案
Simple Network Management Protocol (SNMP) is an Internet Standard protocol for collecting and organizing information about managed devices on IP networks and for modifying that information to change device（）. SNMP is a component of the Internet Protocol Suiteas defined by the Internet（ ）Task Force. SNMP operates in the（ ）layer of the Internet protocol suite. All SNMP messages are transported via User（请作答此空）Protocol. An SNMP-managed network consists of three key components: a) Managed devices, b) （ ）(i.e.，software which runs on managed devices), and c) Network management station (NMS) (i.e.， software which runs on the manager).A.Datum B.Datagram C.DatA.Packet D.DatA.Message
IPsec, also known as the internet Protocol ( ) , defines the architecture for security services for IP network traffic IPsec describes the framework for providing security a the IP layer, as well as the suite of protocols designed to provide that security: through_ ( )_ and encryption of IP network packets. IPec can be used 10 protect network data, for example, by setting up circuits using IPsec ( ), in which all data being sent between two endpoints is encrypted, as with a Virtual (请作答此空) Network connection ;for encrypting application layer data ;and for providing security for routers sending routing data across the public internet. Internet traffic can also be secured from host to host without the use of IPsec, for example by encryption at the ( ) layer with HTTP Secure (TTPS)or an the transport layer wit the Transport Layer Security (TLS)protocol.A.pubic] B.private] C.personal D.proper
Which Internet Protocol(IP) telephony element is best categorizedas a voice application component?（）A、IP telephoneB、Voice gatewayC、Private branch exchange (PBX)D、Advanced audio conferencing software
Open Shortes t Path First (OSPF) is a routing protocol developed for Internet Protocol (IP) networks by the Interior Gateway Protocol (IGP) working group of the Internet Engineering Task Force (IETF). Which two statements best describe the OSPF link - state routing pro tocol?（）A、OSPF sends updates every 10 secondsB、OSPF sends triggered updates when a network change occursC、When a link state is changed, the router that detected the change creates a link - state advertisement (LSA) and propagates it to all OSPF devices using the 224.0.0.6 multicast addressD、OSPF sends summaries of individual link- state entries every 30 minutes to ensure LSDB synchronization
Which two statements are true about RSVP and the InServ QoS model？（）A、a drawback of implementing RSVP is the requirement to migrate to a supporting routing protocolB、RSVP uses DSCP to signal QoS requirements to routers C、RSVP is a routing protocolD、RSVP is an IP protocol that uses IP protocol ID 46， and TCP/UDP ports 3455E、RSVP specifically provides a level of service for rate-sensitive and delay-sensitive trafficF、the flow-based approach of RSVP is ideal for large， scalable implementations such as the public internet
The SCTP layer in the C7 signalling protocol stack is responsible for which of the following:（）A、Establishing a signaling channel between two signaling entities in an ATM networkB、Provide reliable connection for signaling between two IP signaling nodesC、Provide routing for IP signaling messages in an IP signaling network
