Configuring Stunnel - ShoreTel 4500 Installation Manual

Configuring the VPN Concentrator
4.1.4.2 Adjusting the WAN MTU Size
The WAN MTU Size can be adjusted to reduce the latency introduced by large data packets
on a slower link. If the WAN upstream bandwidth is less than 256 Kbps, the MTU size is
automatically reduced to 800 bytes.
The default setting is 1500 bytes for static IP addresses. PPPoE links negotiate the value
automatically although the value can be overridden using this field. If the WAN Upstream
Bandwidth is less than 256 Kbit/s, the MTU size is automatically reduced to 800 bytes.
This only applies if the WAN interface has an IPv4 address assigned.
This option is not available on the 4500/4550 platforms.
4.1.5

Configuring Stunnel

You can configure Stunnel VPN to provide secure VoIP services. Stunnel allows the system
to establish connections on TCP port 443 to allow VPN remote access for VoIP phones.
Stunnel settings are set on the Stunnel Configuration page. To access this page, select
Stunnel from the Configuration Menu.
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Figure 4-10 Stunnel Configuration Page
Caution:
A submit on this page will restart all network services, including the
Stunnel service. All SSL VPN sessions will be terminated.
Chapter 4