多选题Which two Internet Protocol (IP) telephony devices are best categorized as infrastructurecomponents?（）ACall management softwareBMedia Convergence Servers (MCSs)CVoice gatewaysDIP telephones

A. Track DHCP distribution

B. Compare MAC and IP addresses

C. Document Internet access history

D. Identity network devices

A.Call management software

B.Media Convergence Servers (MCSs)

C.Voice gateways

D.IP telephones

A. Set the IP gateway to be used by the network.

B. Perform host discovery used DHCPDISCOVER message.

C. Configure IP address parameters from DHCP server to a host.

D. Provide an easy management of layer 3 devices.

E. Monitor IP performance using the DHCP server.

F. Assign and renew IP address from the default pool.

A global manufacturer of automobile parts wants to implement specialized voice applications to increase productivity and reduce the cost of overseas toll calls. Which Cisco solution best matches this business need?（）

A.Digital subscriber line (DSL)

B.Optical network

C.Wireless local-area network (WLAN)

D.Internet Protocol (IP) telephony

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 seconds

B. OSPF sends triggered updates when a network change occurs

C. 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 address

D. OSPF sends summaries of individual link- state entries every 30 minutes to ensure LSDB synchronization

【A popular service that has attercted the interest of companies and has home users alike is the sending of voice signals over an IP-based network, such as the Internet. The practice of making telephone calls over the internet has had a number of different names, including packet voice, voice over packet, voice over the internet, internet telephone, and Voice over Ip（Voip）. But it appears the industry has settled on the term”Voice ove IP” in reference to the internet protocol, which controls the transfer of data over the internet. There are currently three ways to deliver VoIp to users, the first technique is found at the corporate level. Many companies are offering VoIP systerms that operate over a local area network. These systems involve a fair amount of equipment, such as VoIP servers, special IP-enabled telephones, and routers that can direct telephone calls. Today a large portion of corporate sites have converted their older internal telephone systems to VoIP systems that opreate over a LAN, thus converging two systems into one. A second common solution is the one often encountered at home. Using existing telephones, a special converter is added between the telephone and a high speed internet（DSL or cable modem）connection. The converter digitizes the voice signal and creates a stream of packets that are then sent over an ip connection.The third technique involves smart cell phones. Never cell technologies are all packet-based, thus requiring a telephone call to be converted to digital packets and sending those packets over IP networks.】

From the paragraph above，a popular service that has attracetd the interest of companies and home users,is termed as （） . The data transfer over the Internet is controlled by the （） . At corporate level, many companies have replaced their older internal telephone systerms with （） that oprerate over a local area network.

A、voice over the internet B、voice over packet C、Voice over IP D、internet telephony A、packet B、internet protocol C、industry D、VoIp servers A、VoIP systems B、IP-enablde telephones C、VoIP servers D、routers