1.1.1 Functional comparison

Table 1.1 Function comparison (1) and Table 1.2 Function comparison (2) compare the functions of each network switching mode.

Table 1.1 Function comparison (1)
Function			Redundant line switching mode
Function			Fast switching mode	NIC switching mode
Network control			Makes both of redundant transmission routes active and uses them concurrently. A stream of data is sent on a TCP connection.	Activates and uses one redundant transmission route exclusively and deactivates the other route. If the transmission route is not multiplexed, used the route as it is active.
Fault monitoring	Detectable failures		NIC, cable, switch/HUB, remote host (system down etc.)	NIC, cable, switch/HUB
	Fault monitoring	Monitoring method	Monitors framework between the NIC of the host and that of the remote host. If the frame communication is disrupted, a transmission route failure will be detected.	Monitoring can be done by combining the following 2 monitoring functions. Monitors switch/HUB using the ping command: If there is no response for a certain period of time, a transmission route failure will be detected. Monitors link status of NIC: If the NIC is link down, a transmission route failure will be detected.
	Fault monitoring	Failure detection time	5 to 10 seconds (Default)	When an error is detected by ping: 22 to 27 seconds (Default) When a NIC link down is detected: Using ping monitoring at the same time: 2 to 7 seconds (Default) Using ping monitoring not at the same time: 1 to 6 seconds (Default)
	Recovery monitoring	Monitoring recovery method	Monitors framework between the NIC of the host and that of the remote host. If the frame communication is disrupted, a transmission route failure will be detected.	If a monitoring framework is sent from a standby NIC to an operating NIC, and the standby NIC receives a reply from the operating NIC within a specified time, transmission route recovery will be detected.
	Recovery monitoring	Recovery detection time	1 to 5 seconds (Default)	1 to 30 seconds (Default)
	Fault monitoring start/stop		Automatically starts along with virtual interface activation and stops along with its deactivation.	Automatically starts along with virtual interface activation and stops along with its deactivation. Manual startup or stop of fault monitoring is also allowed with the operational command.
Line switching	Switchover		Automatically disconnects a failed transmission route and uses the other transmission route. Manual disconnection of the failed route is also allowed with the operational command.	Automatically deactivates NIC of a failed transmission route and activates a standby NIC. Manual switching operation is also allowed with the operational command.
Line switching	Switchback		If a failed transmission route is recovered, it will automatically rejoin an ongoing operation. Manual disconnection of the failed route is also allowed with the operational command.	If a failed transmission route is recovered, it will automatically rejoin operation as a standby NIC. Manual rejoining is also allowed with the operational command.
Conditions	Remote hosts		PRIMEQUEST, PRIMERGY, SPARC M10, SPARC Enterprise, PRIMEPOWER, and other systems where GLS's Fast switching mode is running	Arbitrary host
Conditions	IP address		IPv4 address, IPv6 address	IPv4 address, IPv6 address

GLS: Global Link Services

Table 1.2 Function comparison (2)
Function			Redundant line switching mode
Function			Virtual NIC mode	GS linkage mode
Network control			Activates and uses one redundant transmission route exclusively and deactivates the other route.	Makes both of redundant transmission routes active and uses them concurrently. A stream of data is sent on a TCP connection.
Fault monitoring	Detectable failures		NIC, cable, switch/HUB	NIC, cable, HUB, router, remote host (system failure, etc)
	Fault monitoring	Monitoring method	Link status monitoring: Monitors the link status of a physical NIC. If the link is down, the line is considered to be faulty. Network monitoring: Monitors the connectivity between active NIC/standby NIC and switch/HUB. If no response is received within a specified period of time, the line is considered to be faulty.	Monitors a remote host using the ping command. If the communication is disrupted, a transmission route failure will be detected.
	Fault monitoring	Failure detection time	When a NIC link down is detected (Link status monitoring): About 1 second Network monitoring: 14 to 17 seconds (Default)	25 to 30 seconds. (Default)
	Recovery monitoring	Recovery monitoring method	If a monitoring framework is sent from a standby NIC to an operating NIC, and the standby NIC receives a reply from the operating NIC, transmission route recovery will be detected.	Monitors a remote host using the ping command. If the system receives a reply from the remote host within a specified time, transmission route recovery will be detected.
	Recovery monitoring	Detectable recovery time	3 to 5 seconds. (Default)	1 to 5 seconds. (Default)
	Fault monitoring start/stop		Automatically starts along with virtual interface activation and stops along with its deactivation. Manual startup or stop of fault monitoring is also allowed with the operational command.	Automatically starts along with virtual interface activation and stops along with its deactivation. Manual startup or stop of fault monitoring is also allowed with the operational command.
Line switching	Switchover		Automatically deactivates NIC of a failed transmission route and activates a standby NIC. Manual switching operation is also allowed with the operational command.	Automatically disconnects a failed transmission route and uses the other transmission route. Manual switching operation is not supported.
Line switching	Switchback		If a failed transmission route is recovered, it will automatically rejoin operation as a standby NIC. Manual rejoining is also allowed with the operational command.	If a failed transmission route is recovered, it will automatically join communication. Manual rejoining is not supported.
Conditions	Remote hosts		Arbitrary host	GS (Global Server), PRIMEQUEST, PRIMERGY
Conditions	IP addresses		IPv4 address, IPv6 address	IPv4 address