User`s manual

MediaPack SIP User’s Manual 9. Networking Capabilities
Version 4.6 193 June 2005
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 NAT (Network Address Translation) Support
Figure 9-1 below illustrates the supported NAT architecture.
Figure
9-1: NAT Functioning
If the remote gateway resides behind a NAT device, it’s possible that the MediaPack can activate
the RTP/RTCP/T.38 streams to an invalid IP address / UDP port. To avoid such cases, the
MediaPack automatically compares the source address of the incoming RTP/RTCP/T.38 stream
with the IP address and UDP port of the remote gateway. If the two are not identical, the
transmitter modifies the sending address to correspond with the address of the incoming stream.