Sets the frequency (in seconds) with which the
client will send a UDP probe to the traversal
server if a keep alive confirmation has not been
received.

UDP retry count

Sets the number of times the client will
attempt to send a UDP probe to the VCS
Expressway during call setup.

UDP keep alive interval

Sets the interval (in seconds) with which
the client will send a UDP probe to the VCS
Expressway once a call is established, in order
to keep the firewall’s NAT bindings open.

TCP retry interval

Sets the frequency (in
seconds ) with which the
traversal client will send a
TCP probe to the VCS during
call setup.

TCP retry count

Sets the number of times
the client will attempt to
send a TCP probe to the VCS
Expressway during call setup.

TCP keep alive interval

Sets the interval (in seconds)
with which the traversal client
will send a TCP probe to the
VCS once a call is in place,
in order to maintain the
firewall’s NAT bindings.

H.323 protocol

Determines the protocol (Assent or H.460.18)
to be used to traverse the firewall/NAT.
(See

Firewall Traversal Protocols

for more

information.)

H.460.19 demultiplexing Mode

Determines whether or not the same two ports
will be used for media by two or more calls.

: all calls will use the same two ports.

Off

: each call will use a separate pair of ports.

SIP port

Specifies the port on the local VCS Expressway
to be used for SIP calls to and from the
traversal client.

SIP transport

Determines which transport type will be used
for SIP calls to and from the traversal client.

Configuring Traversal Server Zones

SIP mode

Determines whether SIP calls will be allowed to
and from this zone.

H.323 mode

Determines whether H.323 calls will be allowed
to and from the traversal client.

H.323 port

Specifies the port on the local VCS to be used
for H.323 calls to and from the traversal client.

Client authentication
username

If the traversal client
is a VCS, this is
its Authentication
Username. If the
traversal client
is a TANDBERG
Gatekeeper, this is its
System Name.

There must
be an entry
in the

traversal server’s
Authentication
database for this
username. See

Authentication

for

more information.

The default UDP and TCP probe retry
intervals are suitable for most
situations. However, if you experience

problems with NAT bindings timing out, they
may need to be changed.

For full details on how traversal client
zones and traversal server zones work
together to achieve firewall traversal,

see

Firewall Traversal