User's Manual

724-746-5500 | blackbox.com
Page 136
LGB5028A User‘s Manual
724-746-5500 | blackbox.com
Chapter 6: Configuration
Buttons:
Save: Click to save changes.
Reset: Click to undo any changes made locally and revert to previously saved values.
NOTES:
DP level: Every incoming frame is classified to a Drop Precedence level (DP level), which is used throughout the device for
providing congestion control guarantees to the frame according to what was configured for that specific DP level.
PCP: PCP is an acronym for Priority Code Point. It is a 3-bit field storing the priority level for the 802.1Q frame.
DEI: DEI is an acronym for Drop Eligible Indicator. It is a 1-bit field in the VLAN tag.
Actual PCP is PRI column in VLAN tag packet, DEI is CFI column.
PCP values range from 0–7 and can be used to define priority.
DEI value is 0 or 1, user-selected, map to DP value is 0 or 1. When the ingress QoS class value is the same, then the DP level value
defines the priority. The larger DP value will be dropped first.
Example: From Port 1, input 1G Pkts. Set Egress Port 7 Rate to 500M. Port 1 Pkts will include two kinds of packets:
a. PCP & DEI = 0 0 , via configured map to Qos class & DP level = 1, 0
b. PCP & DEI = 0 1 , via configured map to Qos class & DP level = 1, 1
Results will find (a) all passed packets, and (b) all dropped packets.
6.14.2 Port Policing
This section provides an overview of QoS ingress port policers for all switch ports. Use port policing to constrain traffic flows and
mark frames above specific rates. Policing is primarily useful for data flows and voice or video flows, because voice and video
usually maintain a steady rate of traffic.
Web Interface
To display the QoS Port Schedulers in the Web interface:
1. Click “Configuration,” “QoS,” “Port Policing.”
2. Select the port that you want to enable the QoS ingress port policers and type the rate limit condition.
3. Scroll to select the Rate limit Unit from kbps, Mbps, fps and kfps.
4. Click “Save” to save the configuration.