Buffer Tuning - Dell S4048–ON Configuration Manual

OID String
.1.3.6.1.4.1.6027.3.10.1.2.5.1.7
Hardware MIB Buffer Statistics
.1.3.6.1.4.1.6027.3.16.1.1.4
.1.3.6.1.4.1.6027.3.16.1.1.5
.1.3.6.1.4.1.6027.3.16.1.1.6

Buffer Tuning

Buffer tuning allows you to modify the way your switch allocates buffers from its available memory and helps prevent packet drops
during a temporary burst of traffic.
The application-specific integrated circuit (ASICs) implement the key functions of queuing, feature lookups, and forwarding lookups
in hardware.
Forwarding processor (FP) ASICs provide Ethernet MAC functions, queueing, and buffering, as well as store feature and forwarding
tables for hardware-based lookup and forwarding decisions. 1G and 10G interfaces use different FPs.
The following table describes the type and number of ASICs per platform.
Table 111. ASICs by Platform
Hardware
S50N, S50V
S25V, S25P, S25N
As shown in the following example, you can tune buffers at three locations.
1. CSF — Output queues going from the CSF.
2. FP Uplink — Output queues going from the FP to the CSF IDP links.
3. Front-End Link — Output queues going from the FP to the front-end PHY.
All ports support eight queues, four for data traffic and four for control traffic. All eight queues are tunable.
Physical memory is organized into cells of 128 bytes. The cells are organized into two buffer pools — the dedicated buffer and the
dynamic buffer.
• Dedicated buffer — this pool is reserved memory that other interfaces cannot use on the same ASIC or by other queues on the
same interface. This buffer is always allocated, and no dynamic re-carving takes place based on changes in interface status.
Dedicated buffers introduce a trade-off. They provide each interface with a guaranteed minimum buffer to prevent an overused
and congested interface from starving all other interfaces. However, this minimum guarantee means that the buffer manager
does not reallocate the buffer to an adjacent congested interface, which means that in some cases, memory is under-used.
OID Name
chSysPortXfpRecvTemp
fpPacketBufferTable
fpStatsPerPortTable
fpStatsPerCOSTable
FP
2
1
Description
OID displays the temperature of the
connected optics.
NOTE: These OIDs only generate if
you enable the enable optic-
info-update-interval is
enabled command.
View the modular packet buffers details
per stack unit and the mode of allocation.
View the forwarding plane statistics
containing the packet buffer usage per
port per stack unit.
View the forwarding plane statistics
containing the packet buffer statistics per
COS per port.
CSF
0
0
Debugging and Diagnostics
1009