User`s manual

SIP User's Manual 9. Networking Capabilities
Version 5.0 229 October 2006
9 Networking Capabilities
9.1 Ethernet Interface Configuration
Using the parameter ‘EthernetPhyConfiguration‘, users can control the Ethernet connection
mode.
Either the manual modes (10 Base-T Half-Duplex, 10 Base-T Full-Duplex, 100 Base-TX
Half-Duplex, 100 Base-TX Full-Duplex) or Auto-Negotiate mode can be used.
Auto-Negotiation falls back to Half-Duplex mode when the opposite port is not Auto-
Negotiate, but the speed (10 Base-T, 100 Base-TX) in this mode is always configured
correctly. Note that configuring the gateway to Auto-Negotiate mode while the opposite port
is set manually to Full-Duplex (either 10 Base-T or 100 Base-TX) is invalid (as it causes the
gateway to fall back to Half-Duplex mode while the opposite port is Full-Duplex). It is also
invalid to set the gateway to one of the manual modes while the opposite port is either
Auto-Negotiate or not exactly matching (both in speed and in duplex mode). Users are
encouraged to always prefer Full-Duplex connections to Half-Duplex ones and 100 Base-
TX to 10 Base-T (due to the larger bandwidth). It is strongly recommended to use the same
mode in both link partners. Any mismatch configuration can yield unexpected functioning of
the Ethernet connection.
Note that when remote configuration is performed, the gateway should be in the correct
Ethernet setting prior to the time this parameter takes effect. When, for example, the
gateway is configured using BootP/TFTP, the gateway must perform many Ethernet-based
transactions prior to reading the ini file containing this gateway configuration parameter.
To work around this problem, the gateway always uses the last Ethernet setup mode
configured. This way, if users want to configure the gateway to work in a new network
environment in which the current Ethernet setting of the gateway is invalid, they should first
modify this parameter in the current network so that the new setting holds next time
gateway is restarted. After reconfiguration has completed, connect the gateway to the new
network and restart it. As a result, the remote configuration process that takes place in the
new network uses a valid Ethernet configuration.
9.2 Ethernet Interface Redundancy
The Mediant 2000 supports the following redundancy scheme:
At the beginning of the start-up procedure, the gateway tests whether the ‘Primary’
Ethernet interface is connected by checking the existence of the Ethernet link carrier. If it is
connected, the start-up procedure commences as usual. If not, the start-up application tries
the ‘Secondary’ Ethernet interface. If this interface is connected, the whole start-up
procedure is performed using it. If both interfaces are out of order, the start-up procedure
commences using the parameters, tables, and software residing in the gateway’s non-
volatile memory. Note that Ethernet switchover occurs only once during the start-up
procedure (at its beginning). If the Ethernet interface fails after the selection is made, the
gateway does not switch over to the second port.
After start-up has completed and the operational software is running, the gateway
continues to use the Ethernet port used for program load. The gateway switches over from
one Ethernet port to the other one every time an Ethernet link carrier loss is detected on
the active Ethernet port, and if the Ethernet link of the other port is operational. Switchover
takes place only once per link loss (that is, the ‘secondary’ interface stays the active one
even if the ‘primary’ interface has returned to life).
After start-up, the gateway generates a gratuitous ARP message each time a switchover
occurs.