Tag Archives: 1000BASE-SX

What’s the Difference: 10GBASE-SR vs 1000BASE-SX

As the development of fiber optic network, there appears lots of industry standards for fiber optic transceivers. Although transceivers with different standards may have different features and performance, they sometimes can be used in the same switch port. Thus, many people may get confused by these transceivers. For example, 10GBASE-SR and 1000BASE-SX transceivers can both be inserted into the Cisco Catalyst 2960S-48TD-L switch, but the 10GBASE-SR transceiver may not work fine with the 1000BASE-SX module in another switch. Why? This post will discuss 10GBASE-SR vs 1000BASE-SX and whether 10GBASE-SR transceiver can down-support connect to 1000BASE-SX transceiver.

connect 10GBASE-SR to 1000BASE-SX

10GBASE-SR vs 1000BASE-SX

As mentioned above, 10GBASE-SR and 1000BASE-SX are two kinds of industry standards for fiber optic transceivers. This part will introduce them in turns.

10GBASE-SR

10GBASE-SR is defined in the IEEE 802.3 Clause 49 standard, specially designed for multi-mode fiber optic medium that uses 850 nm lasers. It has a data transmission rate of up to 10.3125 Gbps and can be used over multiple cabling options. But the transmission distance may differ as the fiber cable changes. For example, when used over OM1 cabling, the 10GBASE-SR has a maximum working distance of 33 meters, as opposed to 82 meters when applied over OM2 cabling. Nowadays, the 10GBASE-SR module usually applied over OM3 and OM4 cablings to give a more structured optical cabling used in large buildings. And the transmission distance respectively are 300m and 400m.

1000BASE-SX

Like 10GBASE-SR, 1000BASE-SX is also an IEEE 802.3z standard for the multi-mode fiber optic cabling. But it has a minimum transmission distance of 220m and a maximum of 550m. Offering 1Gbps data transmission rate, 1000BASE-SX modules are mainly used to connect high-speed hubs, Ethernet switches, and routers together in different wiring closets or buildings using long cabling runs.

Can 10GBASE-SR Transceiver Down-Support Connect to 1000BASE-SX Transceiver?

10GBASE-SR modules are generally referring to 10GBASE-SR SFP+ transceivers, and 1000BASE-SX modules are usually 1000BASE-SX SFP transceivers. And since SFP+ and SFP transceivers share the same size (as shown below), SFP transceivers can often used in most SFP+ ports (For example, almost all SFP+ ports of Cisco switch can accept SFP transceivers). Then can a 10GBASE-SR SFP+ transceiver down-support connect to the 1000BASE-SX SFP transceiver?

10GBASE-SR vs 1000BASE-SX

10GBASE-SR vs 1000BASE-SX Transceivers

The answer is no. Unlike copper SFP transceivers, 10GBASE-SR SFP+ transceivers do not have such functions as auto-negotiation. In fact, both 10GBASE-SR SFP+ and 1000BASE-SX SFP transceivers can only run at the rated speed fixed by the electro-optical conversion ASIC built into the transceiver hardware. That’s to say, 10GBASE-SR SFP+ transceivers can only run at 10Gbps and 1000BASE-SX SFP transceivers run at 1Gbps. So there is no such fiber link that one end does 1G while the other end does 10G.

10GBASE-SR vs 1000BASE-SX: Have You Known the Differences?

To conclude, although 10GBASE-SR and 1000BASE-SX share something in common, they are totally different Ethernet standards for transceivers. 10GBASE-SR SFP+ transceivers mainly work in 10G links, while 1000BASE-SX transceivers can only run at 1Gbps even though in the SFP+ slot. Thus, it will not work out to connect a 10GBASE-SR SFP+ transceiver with a 1000BASE-SX SFP transceiver.

Related Article: What Is SFP Connector, SFP+ Connector and SFP28 Connector?
Related Article: Choose 10GBASE-T Copper Over SFP+ for 10G Ethernet

Connect Cisco Catalyst 3750 Series Switches to Network

Cisco Catalyst 3750 series switches are widely used in today’s access layer of the network, which can provide Ethernet speed of Gigabit. There are a variety of configurations in this series of Cisco switches. They can fit different applications and offering forward data rates from 32G to 128G by using Cisco StackWise technology. It is an economical solution to many midsize enterprises and office. However, to make full use of these switches, how to connect them to network becomes very important. This post will illustrate Cisco Catalyst 3750 series switches connection in details.

Cisco catalyst 3750 and optics

Do You Know Cisco Catalyst Series Switches?

The ports on switches decide what types of connectors and cables can be connected with the switches. Thus, let’s get a close look at Cisco Catalyst 3750 switches ports details first. As mentioned, one of the biggest advantages is that Cisco Catalyst 3750 can support Cisco StackWise technology. Up to nice physical Catalyst 3750 switches can be interconnected into one logical switch with a high performance of 32G or 128G. This is largely depending on the StackWise ports on the rear panel of the switch as shown in the following picture.

Cisco Catalyst 3750G-48TS rear panel

Another great advantage of Cisco Catalyst 3750 switch is its great flexibility and adaptability owning to its various configurations. The Ethernet ports of Cisco Catalyst 3750 can support data rage from 10M to 1G. For instance, or example, Cisco Catalyst 3750G-12S contains 12 SFP ports, Cisco Catalyst 3750G-24TS-1U has 24 Ethernet 10/100/1000 ports plus 4 SFP uplinks in 1 rack unit (RU) height, Cisco Catalyst 3750G-48PS is armed with 48 Ethernet 10/100/1000 ports with IEEE 802.3af PoE and 4 SFP uplinks. The following picture shows the detailed ports information of Cisco Catalyst 3750G-48TS, which has 48 Ethernet 10/100/1000 ports and 4 SFP uplinks.

Cisco Catalyst 3750G-48TS front panel

Connecting Cisco Catalyst 3750 Series Switch to Network

There are mainly two types of ports on Cisco Catalyst 3750 switches: RJ45 and SFP. Different cables and connectors are used to connect the switches to network. The following will offer detailed information about how to connect these ports.

Cisco Catalyst 3750 Switch 10/100/1000 Ports Connection

10/100/1000 Ports on Cisco Catalyst 3750 are RJ45 ports, which should be connected with copper cables (as shown in the following picture). For different applications, the cable types are also different. For example, when connecting Cisco Catalyst 3750 to workstation, servers, router, the straight-through cables are suggested to use with RJ45 connector. When it the switch is connected to repeaters, crossover cable is recommended. When connecting to 1000Base-T-compatible devices, be sure to use a twisted four-pair, Cat5 cable.

Cisco Catalyst 3750 RJ45 connection
Cisco Catalyst 3750 Switch SFP Module Ports Connection

Most Cisco Catalyst 3750 switches have several SFP ports on their front panel. They can support Gigabit Ethernet, by using SFP modules related. Both copper and fiber optic links can be built with these ports and SFP modules. If connected with fiber optic 1000Base-LX or 1000Base-SX SFP modules a link supporting Gigabit Ethernet based on fiber optic can be built. If connected with copper SFP module like 1000Base-T, a copper link will be built. The following picture illustrates the connections with fiber optic SFP module port and Copper SFP module port from left to right separately.

Cisco catalyst 3750 SFP port connection

Cabling Solution for Cisco Catalyst 3750 Series Switches

More related cables and modules that Cisco Catalyst 3750 switches supporting are listed in the following chart for your reference.

Port Type
Data Rate
Connectors/Modules & Cables
RJ45 Ports 10BASE-T ports  RJ-45 connectors, two-pair Cat 3, 4, or 5 unshielded twisted-pair (UTP)
10BASE-T PoE ports  RJ-45 connectors, two-pair Cat 3, 4, or 5 UTP cabling power pins 1, 2 (negative) and 3, 6 (positive)
100BASE-TX ports  RJ-45 connectors, two-pair Cat 5 UTP
100BASE-TX PoE ports  RJ-45 connectors, two-pair Cat 5 UTP, power on pins 1, 2 (negative) and 3, 6 (positive)
SFP Ports 100M GLC-GE-100FX LC duplex, MMF
GLC-FE-100FX
GLC-FE-100LX LC duplex, SMF
GLC-FE-100BX-D LC simplex, SMF
GLC-FE-100BX-U
1G GLC-SX-MM LC duplex, MMF
GLC-SX-MMD
SFP-GE-S
GLC-EX-SMD LC duplex, SMF
GLC-LH-SM
GLC-ZX-SM
SFP-GE-Z
SFP-GE-L
CWDM SFP
DWDM SFP
GLC-BX-U LC simplex, SMF
GLC-BX-D
GLC-T RJ-45, Cat 5

All the above mentioned products are fully tested in FS.COM Test Center. Please contact sales@fs.com for more details.