Cable and Optics Solution for Catalyst 4948E and Catalyst 4948E-F Switches

Catalyst-4849E-F switch

Cisco Catalyst 4900 series switches were once the most widely deployed ToR (top-of-rack) switches in this industry. This post will introduce the detailed cabling information for two upgrade version of this series switches, which are Cisco Catalyst 4948E and Catalyst 4948E-F. Compared with Catalyst 4900 series switches, the two switches double the uplink bandwidth and provide nonblocking server-to-server traffic with 176G aggregate throughput. Meanwhile, they provide true front to back and back to front airflow with no side or top venting, which can largely reduce the cooling burden of the data centers.

Port Information of Catalyst 4948E and Catalyst 4948E-F

Cisco Catalyst 4948E and Catalyst 4948E-F are very alike. The main difference of the two switches is that the air flow in the Catalyst 4948E goes from the front to the rear of the switch while in Catalyst 4948E-F switch the air flow goes from the rear to the front. The front panel of the two switches is generally the same. Both of the two switches are one-rack-unit (1RU) fixed configuration switch with 48 RJ45 ports of 10/100/1000M for downlink and 4 SFP/SFP+ ports of 1/10G for uplink on the front panel. The following picture shows the detailed port information of Cisco Catalyst 4948E and 4948E-F switch.Catalyst 4948E-F ports information

Downlink Connection for Cisco Catalyst 4948E and Catalyst 4948E-F

The 48 ports on the front panel of Catalyst 4948/4948E-F can support downlink of 10/100/1000M. The great advantage of these ports is that they can configure themselves to operate at the speed of the attached devices. If the attached devices do not support auto-negotiation, the speed and duplex parameters can be set explicitly. A network cable with a RJ-45 plug at both end can connect Cisco Catalyst 4948E/4948E-F switch to the downlink target devices.

Uplink Connection for Cisco Catalyst 4948E and Catalyst 4948E-F

The four uplink SFP/SFP+ ports on Cisco Catalyst 4948E and Catalyst 4948E-F can support both copper and fiber optic transmission of 1G/10G by using different modules and cables. In addition, these ports can also support CWDM SFP transceivers and DWDM SFP transceivers. The following part will introduce the details about how to connect Cisco Catalyst 4948E/4948E-F to 1G network and 10G network.

For 1G connection based on cooper, the 1000BASE-T can be used with RJ45 connector and Cat5 cable. For 1G connection based on fiber optic, there are a wide range of SFP transceivers can be used. Different SFP transceivers should be used with appropriate cables to ensure its best performance. For example, CWDM and DWDM SFP transceivers is usually used with LC connector and single-mode fiber optic cable, thus they can support long distance transmission. The following table presents the solutions for Cisco Catalyst 4948E/4948E-F 1G uplink connection.

Modules Connector & Cable Distance
GLC-T (1000BASE-T) RJ45,Cat5 100m
GLC-SX-MM LC duplex, MMF 550m
GLC-LH-SM LC duplex, SMF 10km
GLC-ZX-SM 70km
CWDM SFP 40-120km
DWDM SFP 40-120km
GLC-BX-D LC simplex, SMF 10km
GLC-BX-U 10km
GLC-BX40-D-I 40km
GLC-BX40-U-I 40km
GLC-BX40-DA-I 40km
GLC-BX80-U-I 80km
GLC-BX80-D-I 80km

For 10G connection, both transceiver and DAC (direct attach cable) can be used, according to the transmission distance requirements. Generally, 10G SFP+ to SFP+ DAC can support transmission distance around 10 meters. If transmission distances are up to hundreds meters or kilometers, fiber optic transceivers should be used. The following table is the detailed solution for Cisco Catalyst 4948E/4948E-F 10G uplink connection.

Modules Connector & Cable Distance
SFP-10G-LRM LC duplex, MMF 220m
SFP-10G-SR 300m
SFP-10G-SR-S 300m
SFP-10G-LR LC duplex, SMF 10km
SFP-10G-LR-S 10km
SFP-10G-ER 40km
SFP-10G-ER-S 40km
SFP-10G-ZR 80km
SFP-10G-ZR-S 80km
DWDM SFP+ 40-80km
SFP-10G-BXD-I LC simplex, SMF 10km
SFP-10G-BXU-I 10km
SFP-10G-BX40D-I 40km
SFP-10G-BX40U-I 40km
SFP-H10GB-CU1M 10G SFP+ DAC Twinax Cable 1m

Please contact or visit FS.COM for more details about the compatible transceivers and DACs for Cisco Catalyst 4948E and Cisco Catalyst 4948E-F switches.