Cisco Systems 186 Manual Do Utilizador
4-8
Cisco ATA 186 and Cisco ATA 188 Analog Telephone Adaptor Administrator’s Guide (SIP)
OL-3410-01
Chapter 4 Basic and Additional SIP Services
Additional SIP Services
Network Timing
You can fine tune your network timing with the following parameters:
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—Use for time-stamping incoming calls (offset from Greenwich Mean Time)
with local time.
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—Use for configuring the IP address of the Network Time Protocol server. NTP
is a protocol built on top of TCP that ensures accurate local time-keeping with reference to radio
and atomic clocks located on the Internet.
and atomic clocks located on the Internet.
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—Use to configure an alternate NTP server IP address.
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—Used to control the connection mode of the SIP protocol.
OutBoundProxy Support
If the OutBoundProxy parameter is a fully qualified domain name (FQDN), and DNS returns multiple
IP addresses, the first IP address is used as the primary outbound proxy and the second IP address as the
secondary outbound proxy. If OutBoundProxy is an IP address or if DNS returns only one IP address,
then a backup outbound proxy is not available. The AltGkTimeOut parameter determines the backup
proxy timeout value for the outbound proxy.
IP addresses, the first IP address is used as the primary outbound proxy and the second IP address as the
secondary outbound proxy. If OutBoundProxy is an IP address or if DNS returns only one IP address,
then a backup outbound proxy is not available. The AltGkTimeOut parameter determines the backup
proxy timeout value for the outbound proxy.
If the backup proxy fails, the Cisco ATA automatically switches back to the primary proxy if the unit
has been using the backup proxy for at least 30 seconds. This effectively prevents the Cisco ATA from
switching indefinitely between failing primary and failing backup proxies for the same transactions.
has been using the backup proxy for at least 30 seconds. This effectively prevents the Cisco ATA from
switching indefinitely between failing primary and failing backup proxies for the same transactions.
Switching between primary and secondary proxies can occur only for initial INVITE and REGISTER
requests. Other requests, such as CANCEL, BYE, ACK, and re-INVITE, do not retry the backup proxy
but give up if the current proxy fails.
requests. Other requests, such as CANCEL, BYE, ACK, and re-INVITE, do not retry the backup proxy
but give up if the current proxy fails.
When OutBoundProxy is enabled, the Cisco ATA determines whether to retry to connect with the
backup OutBoundProxy or backup SIP proxy if the INVITE or REGISTER requests fail. If the reason
for failure is an ICMP error (such as an unreachable host), the Cisco ATA retries with the backup
outbound proxy. If failure is due to timeout while waiting for a response or a 5xx response, the
Cisco ATA retries the backup SIP proxy.
backup OutBoundProxy or backup SIP proxy if the INVITE or REGISTER requests fail. If the reason
for failure is an ICMP error (such as an unreachable host), the Cisco ATA retries with the backup
outbound proxy. If failure is due to timeout while waiting for a response or a 5xx response, the
Cisco ATA retries the backup SIP proxy.
Related Parameter
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Progress Tones
Values for the following parameters (all defined in the
) must be determined based on the country in which the Cisco ATA is located:
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DialTone
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BusyTone
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ReorderTone
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RingBackTone
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CallWaitTone
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AltertTone