Queuing Strategies
- FIFO
- Firs-in-first-out
- Not very smart, not strategic, just sending packets in the order they come in.
- There is no policy there
- Best Effort / Low Latency
- Low Latency is the VIP line
- Fair Queuing
- Imagine 4 different traffic classes
- Break traffic in different traffics
- Weighted Fair Queuing
- Give more preference to certain traffics
- Give different amounts of forwarding capabilities to different traffic flows.
- Encourage Queue starvation
- Group by different traffic pattern
- As traffic comes in we have "if" conditions
- Custom Policies
- Etc.
QoS Marking Review
- QoS markings are set:
- By the end point
- Phone - LLDP (everything that comes in from the phone, it is automatically marked)
- By the edge switch
- By any intermediate devices
- Marking as close to the client the better but we can technically mark everywhere.
- QoS markings are inspected:
- Nothing by default
- You have to turn on QoS, you have to tell it what to look for
- Most things if you ask nice
Queuing Strategy
- Low Latency Queue
- Best Effort
Queuing Strategies
- Queuing capabilities vary based on equipment
- As few as two traffic classes
- Mission critical vs. Not mission critical
- Up to 8 classes, 4 class system is common
Queue Scheduling Concepts
- Fair
- Everybody gets a chance tot talk
- Weighted
- Give less attention to other applications and give more to some
- Starvation