Gigabit backbone switch

In our test of the six Ethernet switches, EDIMAX ES-5800R and LeaPComm6004 switch is not manageable switch, Accton es00008 and creative company Thinker3800 switch are network tube switch, 3Com 4900 is a layer-3 and layer-4 switch, and digital China D-Link DGS3308TG is a layer-3 switch.
Performance first
Among the six products, there are both full copper ports, Full optical fiber ports, and ports with GBIC ports. Among them, 3Com 4900 has 12 1000Base-T copper ports, accton ES4508 with 8 1000Base-SX fiber port, Shenzhou digital D-link DGS-3308TG has 6 1000Base-T port and 2 GBIC interface, Thinker3800 and lipleapcomm6004 are 4 1000Base-SX ports switch. Another point to emphasize is that 3Com 4900 is a layer 3/4 switch, and the DGS-3308TG is a layer-3 switch.
Throughput is the primary factor to consider in terms of performance. Among the six fully Gigabit backbone switches we collected, 3Com 4900, Digital China D-linkDGS-3308TG and EDIMAX ES-5800R reached 512 wire speed in throughput tests of 64-byte, 1518 and 100%-byte frames, accton ES4508 and Thinker 3800 both reach the line speed of 512 bytes and 1518 bytes, and only do not reach the line speed of 64 bytes.
The environment for full-mesh testing is stricter than the one-to-one environment for throughput. Each port of the switch must receive data sent from other ports and send data to other ports, but 3Com 4900, Digital China D-link DGS-3308TG and EDIMAX ES-5800R, these three excellent switches still maintain the true color, no packet loss, reached the 100% line speed. Although some other switches reach the line speed in the throughput test, the line speed is not reached in the full mesh environment, for example, although Accton ES4508 and Thinker 3800 reach the 512 line rate in the throughput test of 1518 bytes and 100% bytes, packet loss occurs in the full mesh test and the line rate is not reached.
For a vswitch with a throughput of 100% wire speed, the frame loss rate test result must be 0. Our test shows that the frame loss rate is not zero in the 64-byte test of Thinker3800 and lipleapcomm6004.
Latency is used to determine the time when a packet passes through the switch. The delay test results of each switch are quite different. The delay time of the EDIMAX ES-5800R of a non-Network-tube switch is only 3.92us in 64 bytes, the network type switch is often longer than the non-network type products Delay Time, and digital D-link DGS-3308TG performance is very good, in the case of 100% line speed 64 bytes delay only 4.52us.
It should be noted that the latency of some switches varies greatly at different rates. Even if their throughput is 100% wire speed, a long delay time may be measured at 100% wire speed. For example, if the throughput of 3Com 4900 with 12 1000Base-T ports is 100% wire speed, the latency value measured when 64-byte frames at 100% wire speed is 55.39us, the result measured at the 98% line rate is 4.07us.
The result of the back-to-back test is the number of frames that are continuously not lost under steady-state load. This value is not significant for a vswitch with a throughput of 100% wire speed. For vswitches whose throughput is not a line rate, the back-to-back test usually reflects the size of the device cache, and the differences between different vswitches are great.
During the line blocking test, we found that all switches support this function. When filtering test error frames, we considered the major error frames, such as small frames, ultra-large frames, CRC error frames, fragments, Alignment errors, and Dribble errors, the results show that all vswitches have the filtering function for these error frames.
We also tested the performance of 3Com 4900 and Shenzhou digital D-link DGS-3308TG on Layer 3. The test results show that the DGS-3308TG performance is very good, in the three-layer throughput and full mesh test is still 100% wire speed, frame drop rate is 0, delay in 100% wire speed, 64 bytes frame is only 4.56us; the 3Com 4900 performance is also good, and only gets the 99.13% line rate value in the 64-byte frame throughput test. In the latency test, the difference in the rate brings a big difference between 3Com4900 and 3Com4900, latency of 64-byte frames and 100% wire speed is 59.41us, while that of 98% wire speed is 4.28us.
Easy installation
We test the Gigabit backbone switch, compared to their powerful forwarding capabilities, their volume is much smaller, especially the digital D-Link DGS-3308TG switch, the performance is very outstanding, it is also a layer-3 switch. Whether physically or mentally, installing a Gigabit Ethernet backbone switch is not an effort-consuming task.
We tested 1-gigabit backbone switches, DGS-3308TG, EDIMAX ES-5800R and 3Com 4900 switches all have 1000Base-T interfaces. The 1000Base-T interfaces of these vswitches support 10/100/Mbit/s adaptive speed and automatic line sequence recognition, eliminating the need for network engineers to connect to vswitches, servers, or routers, this kind of connection should be used for meditation. For some enterprises, the 1000Base-T interface can effectively protect their original investment in wiring.
The gigabit backbone switch we tested is basically fixed and modular. The DGS-3308TG switch has two GBIC interfaces and can adapt to single-mode and multi-mode optical fiber through the GBIC module. The 3Com 4900 switch has an expansion slot on the rear panel. The 1000Base-T/SX/LX module can be inserted into a 16-port Gigabit Switch. The Thinker3800 vswitch is composed of a GE Optical Fiber Module inserted into the four slots of the vswitch. It should be said that it is more flexible in configuration.
Most of the switches we receive have only one AC power supply, while the Accton ES4508 provides a DC power interface, while 3Com 4900 and DGS-3308TG also provide redundant power supply design.
All the netmanager switches that are sent to the test have an option to restore the factory settings. The Thinker3800, DGS-3308TG, and Accton ES4508 switches support the TFTP protocol to upload the existing configuration file of the switch to the TFTP server, or download the previous configuration file of the switch from the TFTP server. If errors occur in the configuration, these two items are useful to engineers. In the 3Com 4900 switch, every time you change the settings, 3Com 4900 automatically saves the settings, which is faster than other manufacturers' dedicated settings to the ROM or RAM.
All the vswitches that support network management can upgrade the software by using TFTP or Xmodem. The 3Com 4900 switch was originally a layer-2 switch. With the help of engineers from 3Com, we upgraded the software. 3Com 4900 was changed to a 3-layer switch ~ A layer-4 switch. You can download the software for free on the website of 3Com.
These vswitches can manually configure the IP address of the vswitch through the serial port, or assign IP addresses to the network management part of the vswitch through DHCP and BOOTP. Once the network management proxy of the vswitch obtains the IP address, you can easily configure the vswitch using Telnet and HTTP. Through the configuration of SNMP on the switch, the network administrator can also use the network management software that supports the SNMP protocol to configure the switch.
Instruction book-textbook?
Several Gigabit backbone switches provided for test are provided with detailed documentation. Here we first introduced the instructions of Digital China D-Link, which is very detailed. The previous section describes the basic knowledge of layer-2 switching and layer-3 routing, and then describes the functions of vswitches in detail. In addition, the specification of the vswitch is Chinese, which is also easy for domestic engineers to read. 3Com 4900 Provides CD and printed instruction documents, which are also very detailed. In addition, the website of 3Com can also download all related file information of the vswitch. The Thinker 3800 switch of the creative company we got provides a CD with a Chinese instruction and detailed content.
Powerful functions

Our evaluation is mainly to measure the performance of GE backbone switches. At the same time, we also consider the functions of switches through configuration and validation tests.
Two of the switches we tested are capable of forwarding on the third layer. Digital China D-Link DGS-3308TG is one of them, we set their eight ports to different VLANs, into different subnets to test its performance, quite good. As a fixed and modular switch, it also supports more complex routing protocols such as OSPF.
Another layer-3 switch is 3Com 4900. After the software is upgraded, It is a layer-3 or layer-4 switch. We tested its L3 performance. In layer-4 mode, it can identify application streams based on TCP port numbers and assign priority to different application streams. For example, assign a high priority to the packets of an SNMP application to ensure network management is feasible. Set a higher priority for an application whose port number is 80.
　
In fact, to ensure high network performance, these Gigabit backbone switches that can be managed support restrictions on broadcast storms. At the same time, all the send and test switches support the traffic control protocol of X 3 to ensure that, in the case of congestion, they negotiate with other network devices to reduce the transmission speed of frames and relieve network congestion. For vswitches that support copper interfaces, they also support back-pressure traffic control in Mbit/s half-duplex mode.
More switches provide IEEE 802.1p priority control, 3Com 4900 and shenzhou.com D-Link DGS-3308TG company switch provides each port 4 priority queue, which is the most out of the test products. The DGS-3308TG of digital D-Link can also assign priority based on the source and destination addresses of data frames. We found that many switches combine the P priority with the Q setting to provide VLAN service quality control. In fact, in addition to ensuring security, VLANs can also improve network performance by limiting broadcast domains.
All vswitches support VLAN 802.1Q. The digital D-Link DGS-3308TG switch supports up to 2048 VLANs. 802.1Q can be tagged on an Ethernet frame so that a VLAN can span multiple switches and one port of a vswitch belongs to multiple VLANs at the same time. All these vswitches support GVRP and GMRP, allowing the host to automatically register to the VLAN and multicast group of the network.
Link aggregation makes the link bandwidth between vswitches and servers very scalable. For example, we can bind two, three, and four Gigabit Links together, multiply the bandwidth of the link. The link aggregation technology can achieve load balancing of different ports, while also ensuring link redundancy. These Gigabit Ethernet switches support up to four link aggregation groups and each group has up to four ports. Generally, when link aggregation is set, we can see which ports belong to one switching chip. Cross-chip settings are not allowed for half of link aggregation.
Both the Spanning Tree Protocol and link aggregation can ensure the redundancy of a network. Set redundant links in a network and use the Spanning Tree Protocol to block the backup link without forming a loop logically. If a fault occurs, the backup link is enabled. However, the Spanning Tree Protocol takes too long to compute. IEEE is developing a new protocol, which is yuan. A 3Com vswitch has an elastic link setting option. Assume that the two links are set as an elastic link group. When one link is disconnected, the switch will quickly start working on another link, the efficiency is higher than the spanning tree algorithm. It is said that the switchover can be completed within one second.
More and more people pay attention to the security of networks. vswitches can isolate illegal customers from the network at the underlying layer. All the vswitches that can be managed support the MAC address filtering function. You can also bind the MAC address with a fixed port and the VLAN. The 3Com and Digital China D-Link vswitches also support higher-level access list control.
In the face of more and more multicast applications, all network-managed switches support IP multicast. Generally, they support IGMP (Internet Group Management Protocol), which intelligently forwards IGMP and multicast packets, instead of broadcasting these packets to all ports.
IGMP Snooping) enables the switch to read IGMP data packets before forwarding to learn which port is a multicast member ). 3Com 4900 and Digital China D-Link DGS-3308TG switch because of support for layer-3 switching, in the IP multicast has stronger support.
Control Gigabit
We have considered that some domestic users will not spend a lot of money to buy some very professional network management software for the time being, so we are very concerned with the management functions provided by the switch itself, they also consider their manageability through actual operations. The Network Management switches we receive support three management methods: out-of-band serial port, in-band Telnet, and HTTP.
String line is the most stable and reliable management method. According to our test results, when a new vswitch is installed, all configuration work starts to connect to the switch through the serial port. Besides the Thinker3800, you can use the serial port to configure all the functions of the switch and view all the information. Compared with Telnet and HTTP, you do not have to worry about losing contact with the vswitch After configuring the VLAN, or failing to log on to the vswitch After replying to the factory settings because the IP address cannot be found. The gigabit backbone Ethernet switch we receive provides a menu-based command line interface. Such a management method does not take too much effort to remember those commands. The only defect is that it is not flexible enough. For example, if you want to set traffic control for all ports, some menu configuration interfaces need to move the cursor to each port for configuration. In the command line mode, a single command completes all the settings. The 3Com 4900 menu is between the command line and the menu mode. Each Command is explained in the following way. The menu configuration interfaces of the switches we tested are well designed, and there is no major difference in the performance of the switches under different loads.
HTTP is our most respected management method. The browser can connect to all vswitches and provide a friendly and intuitive graphical interface. Creative Company's Thinker 3800 can only configure some very simple functions through serial port. Most of the functions and switch management information are provided on the Web. There are help options on the web pages of these vswitches. After clicking these options, you will have a detailed introduction to the configuration content on this page, which is much easier than reading the manual. Shenzhou digital D-Link DGS-3308 TG Switch Web interface delicate, in view the port information, you can use graphical display port utilization. Accton's Web management interface is relatively satisfactory, but its Web method can manage all the functions of the switch. Some manufacturers may experience a slight reduction in Web management compared with Telnet and serial ports. The biggest regret in Web is that no vswitch supports Chinese Web interfaces.
We downloaded the Network Supervisor software from the website of 3Com, through which we can conveniently manage 3Com devices on the Network and view the Load Status of devices and links, it can also notify network administrators through paging and email. In the switch packing box, Accton also provided the company's AccView network management software for managing Accton's network products. Zhouzhou digital D-Link also provides a free download of Dview and professional LinkManager from the website.
In terms of SNMP, all the switches we receive have good support. 3Com vswitches have strong support for RMON and support groups 1, 2, 3, 4, 5, 6, and 9, generally, vswitches support information in groups 1, 2, 3, and 9. In addition to standard MIB such as RFC1213, The es00008 switch of Accton also supports its own MIB.
In the received vswitches, such as 3Com Switch 4900 and Accton ES4508 can also be connected to the modem through a serial port. Users can remotely access the vswitch through dialing through the telephone network for configuration management.