Method and system for network emulation using bandwidth emulation techniques

A system for emulating a network bandwidth condition, the system comprising:

• a first computer having a network interface;
• an emulator link for receiving and sending packets, the emulator link comprising a virtual network link to which the first computer is connected;
• and
• a bandwidth emulation module controlled by the emulator link, wherein the bandwidth emulation module maintains a queue for holding received packets that maintains the queue in one of a blocked stat and an unblocked state and when the queue is in the unblocked state:
• calculating a time cost for transmitting a new packet in accordance with a specified bandwidth configuration;
• calculating a timer expiration time for the new packet based on a current time and the transmitting time cost;
• scheduling the packet timer based on the new packet timer expiration time;
• setting the queue to be in the blocked state;
• and recording the new packet timer expiration time as the virtual time;
• wherein the bandwidth emulation module maintains a virtual time that is updated when a packet timer is scheduled, and wherein the bandwidth emulation module calculates a queued packet timer expiration time that is based on the virtual time.

A computer-readable medium having computer-executable instructions for emulating a network bandwidth condition, the instructions comprising:

• maintaining a queue for holding received packets;
• wherein maintaining the queue further comprises maintaining the queue in one of a blocked state and an unblocked state;
• maintaining a virtual time that is updated when a packet timer is scheduled;
• and
• calculating a queued packet timer expiration time that is based on the virtual time;
• and when the packet timer expires:
• sending a packet associated with the timer;
• if the queue is not empty, for a packet in the queue:
• calculating a time cost for transmitting the queued packet in accordance with a specified bandwidth configuration;
• scheduling a timer for the queued packet based on the queued packet timer expiration time;
• and recording the queued packet timer expiration time as the virtual time.