Questions:
General questions about ATM networks
1. ATM networks use a token bucket scheme to regulate traffic (traffic shaping). A new token is put into the bucket every 1 usec so ATM cells can be sent during this period. The data payload of ATM cells is 48 bytes.
What is the maximum sustainable net (or effective) data rate?
2. A bridge between an 802.3 LAN and an 802.4 LAN has a problem with intermittent memory errors. Can this problem cause undetected errors with transmitted frames, or will these all be caught by the frame checksum?
3. A virtual circuit is newly set up in an ATM network. Between the source and destination hosts lie 3 ATM switches. How many messages (including acknowledgments) will be sent to establish the circuit (or connection)?
4. When a 1024-bytes message is sent with AAL 3 / 4, what is the efficiency achieved? In other words, what fraction of the bits transmitted are useful data bits? Repeat for AAL 5.
5. A CPU executes instructions at the rate of 100MIPS. Data can be copied 64 bits at a time, with each word copied costing 4 instructions. If an incoming packet has to be copied twice, can this system handle a 10-Gbps line? For simplicity, assume that all instructions, including those instructions that read or write memory, run at the full 100 MIPS rate.