Phone Cards Digest

The main VoIP protocol that falls into this category is Skype. As the protocol
implementation is currently unknown and the packet payload encrypted, the best way to monitor this protocol is to threat it as special eDonkey protocol communication.

Typically Skype is detected as follows:

• The underlying protocol must be eDonkey. This can be detected by dissecting the initial session payload as described in [karagiannis], and partially relying on the default port being used. Patterns searching for Skype detection has been implemented using the popular PCRE [pcre] library. This library that allows patterns to be efficiently searched into into a data buffer, has been used to search for Skype pattern into the packet payload. The protocol pattern definition has been borrowed by the popular l7-filter [l7-filter] tool that includes several patters not limited only to P2P/ VoIP protocols. (continue reading…)

LDC DILEMMA
• Political constraints in more developed areas of “bypassing” the incumbent with VoIP and thus regulatory or even criminal restraints of development. Control/loss of intl traffic.
• Tension between graduation of urban areas and commerce to next higher level of global market access and deploying basic access to rural areas—the universal access challenge

REGULATORY CHALLENGE
• Getting the courage to regulate creatively and around the traditional formats
• Encouraging private-municipality partnerships
• Exempting certain regions out of restrictive regulation
• Balancing true consumer needs with investment realities (continue reading…)

A best-effort network provides just what its name describes – a network that does its best to deliver packets in a timely manner. It is the least complex and costly network approach and is the design most networks use today. Best-effort networks work well for non-sensitive traffic types such as Web browsing and e-mail since delays in these services generally do not significantly impact the user experience.

Best-effort networks leverage Interior Gateway Protocol (IGP) technologies such as Open Shortest Path First (OSPF) and Intermediate System to Intermediate System (IS-IS) to determine paths for routing packets between hosts. IGP protocols use a Shortest Path First (SPF) algorithm to build routing tables. The routing engine references these routing tables at each router hop traversed by the packets. (continue reading…)