Brocade built the VDX 6740 and VDX 6940 as fixed switches whose working port count is set by license, so a part number names both the hardware and how much of it is turned on. This guide sets the VDX 6740, the copper VDX 6740T and the two VDX 6940 platforms side by side, then covers the licenses, the power and the airflow letters. Every figure comes from Brocade and Extreme data sheets, technical specifications, installation guides and release notes, listed under Sources.
The short answer
Choose the port first: SFP+ fiber on the VDX 6740, 10GBASE-T copper on the VDX 6740T, 40 GbE QSFP+ on the VDX 6940-36Q, or 96 10 GbE SFP+ ports with 40 and 100 GbE uplinks on the VDX 6940-144S. Then choose how many ports are licensed: the number after the model is the count enabled. Then match F or R to the rack: F units exhaust at the non-port side and R units at the port side.
The models side by side
| Model | Ports | Switching capacity | Latency | Size |
|---|---|---|---|---|
| VDX 6740 | 48 x 1/10 GbE SFP+, 4 x 40 GbE QSFP+ | 1.28 Tbps, 960 Mpps | 850 ns | 1U |
| VDX 6740T | 48 x 10GBASE-T, 4 x 40 GbE QSFP+ | 1.28 Tbps, 960 Mpps | 3 microseconds | 1U |
| VDX 6940-36Q | 36 x 40 GbE QSFP+ (144 x 10 GbE with breakout) | Not stated | Not stated | 1U |
| VDX 6940-144S | 96 x 10 GbE SFP+, 12 x 40 GbE QSFP+ | Not stated | 800 ns | 2U |
VDX 6740: SFP+ ports
The VDX 6740 has 48 1/10 GbE SFP+ ports and 4 40 GbE QSFP+ ports, each of which breaks out to 4 10 GbE ports; 32 of the SFP+ ports can be configured as Fibre Channel FlexPorts. It gives 1.28 Tbps, 960 Mpps and 850 ns of latency port to port. Base models enable 24 ports, and upgrade licenses bring the count to 48, or 64 with the QSFP+ ports broken out; the BR-VDX6740-2X40G-POD is a 2 x 40 GbE Ports on Demand license for the VDX 6740 and VDX 6740T. It runs on two hot-swappable 250 W AC supplies, each with 3 integrated fans, at 100 to 240 V AC nominal, and has a 1.5 GHz PowerPC CPU and an RJ-45 out-of-band management port at 1 Gbps. It measures 1.75 x 17.32 x 16.14 in (4.32 x 43.99 x 40.99 cm) and weighs 8.66 kg (19.10 lb) with power supplies and fans and no transceivers; Brocade lists the models as shipping with no optics.
VDX 6740T: copper ports
The VDX 6740T is the copper VDX 6740: 48 10GBASE-T ports that run at 100 Mbps, 1 Gbps or 10 Gbps and 4 40 GbE QSFP+ ports, with 1.28 Tbps, 960 Mpps and 3 microseconds of latency. Base models enable 24 ports and upgrade licenses bring the count to 48. It runs on two hot-swappable 500 W AC supplies with 5 separate hot-swap fans, and it is a deeper box than the VDX 6740: 1.68 x 17.22 x 21.12 in (4.27 x 43.74 x 53.65 cm), at 10.82 kg (23.85 lb). The VDX 6740T-1G has 48 Base-T ports at 100 Mbps or 1 Gbps, and a license enables 10 Gbps in steps of 16, 32 and 48 ports.
VDX 6940: 40 GbE and high density 10 GbE
The 1U VDX 6940-36Q has 36 40 GbE QSFP+ ports, or 144 10 GbE ports with breakout cables; the BR-VDX6940-24Q has 24 enabled, and a 40 GbE Port Upgrade license raises them to 36. It has a 1.5 GHz P3041 quad core CPU, 16 GB of DDR3, a 4 MB boot flash and a 16 GB e-USB compact flash, and five field-replaceable fan assemblies of two fans each, 10 per system; the XBR-FAN-40-R is a 40 mm port-side exhaust fan for it. It weighs 8.9 kg (19.6 lb) empty and 10.1 kg (22.3 lb) fully loaded, with a nominal 71 dBA and a maximum of 88 dBA.
The 2U VDX 6940-144S has 96 10 GbE SFP+ ports and 12 40 GbE QSFP+ ports, up to 4 of them usable at 100 GbE, with 800 ns of latency and a 24 MB on-chip buffer. The BR-VDX6940-64S has 64 ports active, and Ports On Demand licenses raise it to 144. It has a 1.5 GHz P4080 8-core CPU, four field-replaceable fan assemblies of one fan each and two load-sharing supplies of 1100 W each, and weighs 15.46 kg (34.10 lb) empty.
Airflow: the F and R letters
F models take air in at the port side and exhaust at the non-port side; R models take air in at the non-port side and exhaust at the port side. In Extreme's VDX 6740 installation guide an F part carries the green E symbol and an R part the orange I, and every fan and power supply in a chassis must carry the same airflow: fitting a mismatched one raises a console warning. A replacement fan or supply has to carry the same letter as the switch.
What to check before you buy
- The port type: SFP+ on the VDX 6740, 10GBASE-T on the VDX 6740T, QSFP+ on the VDX 6940-36Q.
- The licensed count in the part number: 24, 48 or 64 on the VDX 6740, 24 or 36 on the VDX 6940-36Q, 64 or 144 on the VDX 6940-144S.
- The F or R letter, on the switch and on every spare fan and supply.
- The rack depth for a VDX 6740T, which is deeper than the VDX 6740.
- Optics: the switches list no optics. The 40G-QSFP-LR4, a 40 GbE QSFP+ optic with 10 km of reach, is listed for VDX switches.
Where to look
Each family has its own page listing what is in stock: the VDX 6740, VDX 6740T and VDX 6940, with the whole Brocade VDX line and Brocade transceivers. Pages in stock today include the BR-VDX6740-48-F, the BR-VDX6740-24-R, the BR-VDX6740T-48-F, the BR-VDX6940-36Q-AC-F and the BR-VDX6940-144S-AC-R. For the whole maker, read the Brocade and Ruckus guide. Request a quote for a part that is not listed, or sell the switches you retire.
Sources
- ExtremeSwitching VDX 6740 Technical Specifications
- ExtremeSwitching VDX 6740 Hardware Installation Guide
- Brocade VDX 6740, 6740T, and 6740T-1G Switches data sheet (archived copy)
- ExtremeSwitching VDX 6940 Technical Specifications
- ExtremeSwitching VDX 6940 Hardware Installation Guide
- Network OS 7.2.0a for VDX Release Notes
- Extreme Routing MLX Series Hardware Installation Guide (2018)
