8. uses a proprietary Internet telephony (VoIP) network called the Skype protocol
9. the main difference between Skype and standard VoIP clients is that Skype operates on a peer-to- peer model, rather than the more usual client– server model
17. 1536 to 2048 bit RSA to negotiate symmetric AES keys
18.
19. Normally, a string of characters represented using a fixed number of bits per character, as in the ASCII code
20. separating the input into component symbols and replacing each with a code, arithmetic coding encodes the entire message into a single number, a fraction n where (0.0 ≤ n < 1.0)
21.
22. subsequent startups, a SC only sent a HTTP 1.1 GET request to the server to determine if a new version is available
32. is used on the TCP connection between all clients and servers
33. flap sequence numbers are used for errors detection Offset Field Type/Size (in bytes) Remarks 00 FLAP ID Byte/1 Always contains 2A. It is mark of packet start. 01 Channel Byte/1 1 = login, 2 = SNAC layer, 3 = error, 4 = disconnect 02 Number in sequence Int 16/2 Incremented by 1 each time a packet sent. Wraps to 0 after FFFF 03 Data size Int 16/2 Size does not include FLAP header FLAP Header OSCAR I.
38. 16-bit value for the length of the Value field, and then the actual data in the Value field (variable length)
39. TLVs make sending a variable length string like "nickname@gmail" as simple as defining a TLV with values {0x0011, 0x000c, "nickname@gmail.com"}. OSCAR II.