Information here is by rumor, innuendo and extrapolation. Manufacturers rarely put info on packet buffers in their data sheets.
|
"Shared memory" means that the hardware permits buffers to be used by any port that needs them. In a shared memory design it is not possible to let ALL the memory go to virtual output queued packets. There would be no room for new arrivals which would lead to head of line blocking.
|
Max buffer queue depth requires that QoS be disabled so that all packet memory can be put into a single queue.
|
Model
|
Port Type
|
RX Queue
|
TX Queue
|
Total Buffer
|
RX Buffer
|
TX Buffer
|
Shared Memory
|
Juniper QFX3500 trident
|
48 SFP+ and 4 QSFP
|
12Q
|
|
9 MB
|
|
5? MB
|
Brocade FCX624S
|
24Gig-E w 4 SFP+
|
8Q
|
|
2 MB
|
|
1.04 MB max to 1 port
|
HP A5800-24G
|
24Gig-E w 4 10Gb/s
|
8Q
|
|
4 MB
|
|
4 MB
|
HP E6600-24G-4XG
|
24Gig-E w 2 10Gb/s
|
8Q
|
|
18 MB for GE
|
|
18 MB
|
Arista 7124SX
|
24 x SFP+
|
8Q
|
|
2 MB/switch
|
shared
|
1.7 MB
|
Arista 7148SX
|
48 SFP+
|
8Q
|
|
8 MB/switch
|
|
6 MB
|
IBM BNT G8052
|
48 GE + 4 SFP+
|
8Q
|
|
4 MB/switch
|
|
4 MB
|
Dell 8024
|
24 SFP+
|
2Q
|
|
2 MB
|
|
|
Dell 6248
|
48 Gig-E, 4 x SFP+
|
8Q
|
|
unknown
|
|
unknown
|
Dell 7024
|
24 Gig-E, 4 x SFP+
|
8Q
|
|
4 MB
|
|
4 MB
|
Catalyst 3750G-48TS
|
6 ASICs w/ 8 GE ports ea
|
8Q
|
1P3Q3T
|
576KB per ASIC
|
192KB per ASIC
|
384KB per ASIC
|
Catalyst 3750E & 3650E
|
ASIC support 24 GE ports or 2 x 10G
|
2Q
|
1P3Q3T
|
2750KB per ASIC
|
750KB per ASIC
|
2MB per ASIC
|
Catalyst 4948E
|
48 GigE + 4 SFP+
|
4
|
|
17.5 MB
|
|
Max 16 MB to 1 port
|
|
Virtual Output Port queuing
|
Force10 S60
|
48Gig-E w 4 10Gb/s
|
8Q
|
|
1250 MB
|
25 MB/port
|
|
Arista 7048
|
48Gig-E w 4 10Gb/s
|
8Q
|
|
768 MB
|
16 MB/port?
|
|
Cisco Nexus 5010
|
26 SFP+
|
8
|
1 (I think)
|
480 KB per port
|
480 KB
|
borrows from RX
|
|
Catalyst 6500 bits and pieces
|
WS-SUP720-3B
|
2 x GE
|
1P1Q4T
|
1P2Q2T
|
512KB
|
80KB
|
432KB
|
VS-S720-10G-3C
|
2 x 10GE
|
2Q4T
|
1P3Q4T
|
191.8MB
|
105MB
|
88MB
|
VS-S720-10G-3C
|
3 x 1GE
|
2Q4T
|
1P3Q4T
|
17.7MB
|
9.6MB
|
8.1MB
|
CEF720 Modules
|
WS-X6716-10GE-3C
|
16 x 10GE
|
8Q4T
|
1P7Q4T
|
199MB
|
109MB
|
90MB
|
WS-X6716-10GE-3CXL
|
16 x 10GE
|
8Q4T
|
1P7Q4T
|
199MB
|
109MB
|
90MB
|
WS-X6708-10GE-3CXL
|
8 x 10GE
|
8Q4T
|
1P7Q4T
|
199MB
|
109MB
|
90MB
|
WS-X6708-10GE-3C
|
8 x 10GE
|
8Q4T
|
1P7Q4T
|
199MB
|
109MB
|
90MB
|
WS-X6704-10GE
|
4 x 10GE
|
1Q8T
|
1P7Q8T
|
16MB
|
2MB
|
14MB
|
WS-X6724-SFP
|
24 x GE SFP
|
1Q8T
|
1P3Q8T
|
1.3Mb
|
166KB
|
1.2MB
|
WS-X6748-GE-TX
|
48 x GE TX
|
1Q8T
|
1P3Q8T
|
1.3Mb
|
166KB
|
1.2MB
|
WS-X6748-SFP
|
48 x GE SFP
|
1Q8T
|
1P3Q8T
|
1.3Mb
|
166KB
|
1.2MB
|
WS-X6516-GBIC
|
16 x GE GBIC
|
1P1Q4T
|
1P2Q2T
|
512KB
|
73KB
|
439KB
|
WS-X6516A-GBIC
|
16 x GE GBIC
|
1P1Q4T
|
1P2Q2T
|
1MB
|
135KB
|
946KB
|
WS-X6516-GE-TX
|
16 x 10/100/1000
|
1P1Q4T
|
1P2Q2T
|
512KB
|
73KB
|
439KB
|
WS-X6524-100FX-MM
|
24 x 100FX Multimode
|
1P1Q0T
|
1P3Q1T
|
1.1MB
|
28KB
|
1088KB
|
WS-X6548-RJ-21
|
48 x 10/100
|
1P1Q0T
|
1P3Q1T
|
1.1MB
|
28KB
|
1088KB
|
WS-X6548-RJ-45
|
48 x 10/100
|
1P1Q0T
|
1P3Q1T
|
1.1MB
|
28KB
|
1088KB
|
WS-X6548-GE-TX
|
48 x 10/100/1000
|
1Q2T shared between 8 ports
|
1P2Q2T shared between 8 ports
|
1.4MB shared between 8 ports
|
185KB shared between 8 ports
|
1.2MB shared between 8 ports
|
WS-X6548V-GE-TX
|
48 x 10/100/1000 with Cisco inline power
|
1Q2T shared between 8 ports
|
1P2Q2T shared between 8 ports
|
1.4MB shared between 8 ports
|
185KB shared between 8 ports
|
1.2MB shared between 8 ports
|
WS-X6548-GE-45AF
|
48 x 10/100/1000 with 802.3af inline power
|
1Q2T shared between 8 ports
|
1P2Q2T shared between 8 ports
|
1.4MB shared between 8 ports
|
185KB shared between 8 ports
|
1.2MB shared between 8 ports
|
dCEF256 Modules
|
WS-X6816-GBIC
|
16 x GE GBIC
|
1P1Q4T
|
1P2Q2T
|
512KB
|
73KB
|
439KB
|
Classic Modules
|
WS-X6024-10FL-MT
|
24 x 10Base FL
|
1Q4T
|
2Q2T
|
64KB
|
8KB
|
56KB
|
WS-X6148-RJ-21
|
48 x 10/100
|
1Q4T
|
2Q2T
|
128KB
|
16KB
|
112KB
|
WS-X6148-RJ-21V
|
48 x 10/100 with Cisco inline power
|
1Q4T
|
2Q2T
|
128KB
|
16KB
|
112KB
|
WS-X6148-21AF
|
48 x 10/100 with 802.3AF inline power
|
1Q4T
|
2Q2T
|
128KB
|
16KB
|
112KB
|
WS-X6148-RJ-45
|
48 x 10/100
|
1Q4T
|
2Q2T
|
128KB
|
16KB
|
112KB
|
WS-X6148-RJ-45V
|
48 x 10/100 with Cisco inline power
|
1Q4T
|
2Q2T
|
128KB
|
16KB
|
112KB
|
WS-X6148-45AF
|
48 x 10/100 with 802.3AF inline power
|
1Q4T
|
2Q2T
|
128KB
|
16KB
|
112KB
|
WS-X6148-GE-TX
|
48 x 10/100/1000 no jumbo
|
1Q2T shared between 8 ports
|
1P2Q2T shared between 8 ports
|
1.4MB shared between 8 ports
|
185KB shared between 8 ports
|
1.2MB shared between 8 ports
|
WS-X6148A-GE-TX
|
48 x 10/100/1000 jumbo 9216
|
1Q2T shared between 8 ports
|
1p3q8t shared between 8 ports
|
5.5 MB per port
|
120KB
|
5.4MB
|
WS-X6148V-GE-TX
|
48 x 10/100/1000 with Cisco inline power
|
1Q2T shared between 8 ports
|
1P2Q2T shared between 8 ports
|
1.4MB shared between 8 ports
|
185KB shared between 8 ports
|
1.2MB shared between 8 ports
|
WS-X6148-GE-45AF
|
48 x 10/100/1000 with 802.3AF inline power
|
1Q2T shared between 8 ports
|
1P2Q2T shared between 8 ports
|
1.4MB shared between 8 ports
|
185KB shared between 8 ports
|
1.2MB shared between 8 ports
|
WS-X6224-100FX-MT
|
24 x 100FX
|
1Q4T
|
2Q2T
|
64KB
|
8KB
|
56KB
|
WS-X6248-RJ-45
|
48 x 10/100
|
1Q4T
|
2Q2T
|
64KB
|
8KB
|
56KB
|
WS-X6248-TEL
|
48 x 10/100 (RJ21)
|
1Q4T
|
2Q2T
|
64KB
|
8KB
|
56KB
|
WS-X6248A-TEL
|
48 x 10/100 (Telco)
|
1Q4T
|
2Q2T
|
128KB
|
16KB
|
112KB
|
WS-X6316-GE-TX
|
16 x 10/100/1000
|
1P1Q4T
|
1P2Q2T
|
512KB
|
73KB
|
439KB
|
WS-X6324-100FX-MM
|
24 x 100FX
|
1Q4T
|
2Q2T
|
128KB
|
16KB
|
112KB
|
WS-X6324-100FX-SM
|
24 x 100FX
|
1Q4T
|
2Q2T
|
128KB
|
16KB
|
112KB
|
WS-X6348-RJ-45
|
48 x 10/100
|
1Q4T
|
2Q2T
|
128KB
|
16KB
|
112KB
|
WS-X6348-RJ-45V
|
48 x 10/100 with Cisco inline power
|
1Q4T
|
2Q2T
|
128KB
|
16KB
|
112KB
|
WS-X6348-RJ-21V
|
48 x 10/100 with Cisco inline power
|
1Q4T
|
2Q2T
|
128KB
|
16KB
|
112KB
|
WS-X6408-GBIC
|
8 a GE GBIC
|
1P1Q4T
|
1P2Q2T
|
512KB
|
80KB
|
432KB
|
WS-X6408A-GBIC
|
8 x GE GBIC
|
1Q4T
|
2Q2T
|
512KB
|
73KB
|
439KB
|
WS-X6416-GE-MT
|
16 x 10/100/1000
|
1P1Q4T
|
1P2Q2T
|
512KB
|
73KB
|
439KB
|
WS-X6416-GBIC
|
16 x GE GBIC
|
1P1Q4T
|
1P2Q2T
|
512KB
|
73KB
|
439KB
|
10. Appendix Two-QoS Summary Feature List
The following list provides a summary of the QoS features found in the Catalyst 6500, where the feature is processed and if the feature is applied on ingress or egress.