1. Brian Hixenbaugh Network Managment

2. My Home Network

3. My Plan… N.A.S. (1 TB External Hard Drive) Connects to Router via Ethernet (Has IP Address) Stores movies, television shows, etc. Laptop Connected to TV (Downstairs) Wirelessly stream content from N.A.S. or Internet Display on television Roommate’s Laptop (iPhone, etc.) Independently use Internet or N.A.S. as well

4. It Works! (Almost) Need to Implement QoS (Quality of Service) Router Inspects Packets – Prioritizes Video, VoIP Low Priority – P2P Improve Radio Performance Increase TX power, Increase Beacon Interval Expensive Commercial Routers Offer These Features Cheap home routers can offer these features as well with replacement software!

5. Embedded Systems A Router is a “Mini” Computer with: CPU RAM Hard Drive (Flash Chip) Open Source Software Can Replace Factory Software to Provide More Features OpenWRT Tomato DD-WRT

6. Netgear WGR614

7. DD-WRT

8. “Flashing” New Software Similar to a PC Boot program (CFE) Kernal (linux!) Software (dd-wrt) Upload via Router’s Web GUI (Ethernet) Software not always compatible with all makes & models of routers Flash memory locations can be different There can be problems!

9. Bricked

10. Fix a Brick with JTAG Joint Test Action Group or Boundary-Scan IEEE Standard for communicating with embedded systems Allows issuing commands directly to Processor Allows directly programming Flash Memory Allows a PC to Communicate for Debugging Requires parallel port on PC, special interface device, and communication software

11. Common Firmware Environment CFE contains information for Ethernet (MAC addr.) Also contains information to boot Kernal If damaged, must be replaced by JTAG CFE is small (~128k) but JTAG is slow – can take 5-10 minutes to upload Kernal & software are much larger (2-3MB) not practical to send via JTAG Once CFE is uploaded and running, remaining software can be quickly flashed via Ethernet using TFTP (Trivial File Transfer Protocol)

12. No Happy Ending Could not successfully reload factory software Possible hardware problems (bad flash chip, CPU) Still a Brick!