35. If the congestion window size is 20KB, and the receive window size is 30KB, what is the maximum bytes can the TCP entity transmit?
A. 20KB B. 30KB C. 50KB D. 10KB
36. Port numbers below ________ are called well-known ports and are reserved for standard services.
A. 256 B. 1024 C. 4096 D. 1000
37. ________, which are overlay networks on top of public networks but with most of the properties of private network.
A. PBX B. VPN C. CDMA 1X D. GPRS
38. The problem of running out of IP addresses is not a theoretical problem that might occur at some point in the distant future. Some people felt that a quick fix was needed for the short term. This quick fix came in the form of ____________________. A. IP6 B. DHCP C. RARP D. NAT
39. Public-key algorithms have the property that ____________________ keys are used for encryption and decryption and that the decryption key cannot be derived from the encryption key. These properties make it possible to publish the public key. A. one time B. random C. same D. different
40. The main public-key algorithm is ____________________ which derives its strength from the fact that it is very difficult to factor large numbers. A. DES B. AES C. MD5 D. RSA
41. Various schemes have been devised for digital signatures, using both symmetric-key and ________-key algorithms.
A. public B. private C. one time D. one way
42. Often, authentication is needed but secrecy is not, based on the idea of a one-way hash function that takes an arbitrarily long piece of plaintext and from it computes a fixed-length bit string. This hash function, MD, often called a ________.
A. message digest B. packet-switched C. message-detect D. mini data
43. URL(Uniform Resource Locator) have three parts: the ________, the DNS name of the machine on which the page is located, and a local name uniquely indicating the specific page. A. protocol B. address C. port number D. name
44. HTTP1.1, which supports ________ connections. With them, it is possible to establish a TCP connection, send a request and get a response, and then additional requests and get additional response.
A. one time B. persistent C. stop and wait D. one-way
45. _______, when it is used, a bad frame that is received is discarded, but the good frames received after it are buffered.
A. selective repeat B. go back N C. sliding window D. stop and wait 46. How does the FDM multiplexing schemes work like?
A. each user having exclusive possession of some band
B. each user take turns, periodically getting the entire bandwidth for a litter burst of time C. each user transmit over the entire frequency spectrum all the time with different coding D. each user transmit over a shared fiber using different wavelength
47. When we use a modem, which use 16 phases signal to modulation, then how much can we get the maximum data rate in a 2400 baud channel (in noiseless channel)?
A. 400bps B. 2400bps C. 9.6kbps D. 14.4kbps
48. ______ is a small java program that has been compiled into binary instruction running in JVM,