---
# System prepended metadata

title: <center><i class="fa fa-edit"></i> QoS Fundamentals Cont.  </center>
tags: [Internship]

---

# <center><i class="fa fa-edit"></i> QoS Fundamentals Cont.  </center>
###### tags: `Internship`
:::info
**Goal:**
- [x] Understand fundamentals of QoS applications Cont.
- [x] QoS Architecture Preview

**Resources:**
[Notes Page](https://hackmd.io/@j-chen/rkUz8DeUw)
:::
### QoS Fundamentals Cont.
- Quantitative service: AKA "guaranteed"
    - Delivers hard QoS
    - Highest QoS
    - Guarantees network performance in deterministic/statistical terms
    - Good for mission-critical applications
- Qualitative service: AKA "differentiated"
    - Soft/relative QoS
    - Ex: priority service
- Best effort servce: no guarantees
    - All traffic equal
    - Good for data traffic (email, etc.)
    - Lowest level service
- Per-flow QoS: assurance to individual flows (applications)
    - Per-flow classification: differentiates different flows
- Per-class QoS: classify groups based on criteria (QoS requirement, organization, app type, protocol family)
    - Assurance to class
        - Everything in same class has same QoS
    - Per-class classification
- Realization of QoS: bandwidth planning
    - Bandwidth over-provisioning: upgrade infrastructure if you need more
        - Price: very costly
    - Bandwidth management via QoS mechanisms
        - QoS mechanisms:
            - Classification
            - Admission control
            - Channel access
            - Resource reservation
            - Scheduling
            - Policing
### QoS Architecture Preview
![](https://i.imgur.com/mziHXr7.png)