serialization delay
overrun
full buffers and queues
propagation delay
shaping delay
TCP header errors
第1题：
A.Delay should be no more than 10 ms.
B.Loss should be no more than1 percent.
C.Jitter should be less then 40 ms.
D.Managed bandwidth is strongly recommended for voice control traffic.
第2题：
What are two design guidelines for VoIP networks? （）
第3题：
A.a packet of prawn
B.two packets of prawn
C.a packet of prawns
第4题：
What are two reasons to implement H·323 gatekeepers？（）
第5题：
Jitter is causing problems with the VOIP application in the network. What causes network jitter？（）
第6题：
【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
第7题：
Which two statements best describe Cisco IOS IP SLA？（）
第8题：
A. 802.1X
B. video messaging
C. IPsec
D. VoIP
第9题：
Jitter is causing problems with the VOIP application in the Company network. What causes network jitter？（）
第10题：
Which two networking infrastructure characteristics are most likely to distinguish video requirements （such as Cisco TelePresence） from voice requirements？（）