Cisco Systems Linksys PAP2 Manual De Usuario

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parameter is useful only if the primary and backup 
proxy server list is provided to the PHONE 
ADAPTER via DNS SRV record lookup on the 
server name. (Using multiple DNS A record per 
server name does not allow the notion of priority 
and so all hosts will be considered at the same 
priority and the PHONE ADAPTER will not attempt 
to fall back after a fail over) 
 
Subscriber Information 
Display Name 
Subscriber’s display name to appear in caller-id 
Str23 
 
User ID 
Subscriber’s user-id. Usually a E.164 number 
Str47 
 
Password Subscriber’s 
a/c password 
Str23 
 
Auth ID 
Subscriber’s authentication ID 
Str39 
 
Use Auth ID 
If set to “yes”, the pair <Auth ID> and <Password> 
are used for SIP authentication. Else the pair <User 
ID> and <Password> are used. 
Bool No 
 
 
4.5. 
Configuration for NAT Traversal 
In general, there are 3 general approaches to enable NAT traversal available on the PHONE 
ADAPTER: STUN (Simple Traversal of UDP through NAT), Using an outbound rewriting "proxy", and 
manual configuration. If the PHONE ADAPTER is not "behind" a NAT, the default settings should be 
used. 
 
Note: The Linksys model RT31P2 includes NAT (Network Address Translator) functionality. As long 
as the IP address of the "WAN Port" is a public IP address, the RT31P2 can be configured with all 
NAT Traversal features (NAT Traversal off), since the PHONE ADAPTER portion shares the same IP 
address as the WAN Port. If the address obtained on the WAN Port is already a private address, then 
the RT31P2 still needs to be configured for NAT traversal. 
 
The Outbound Proxy approach works through more than 99% of NATs, but it requires the service 
provider to relay RTP media packets for every call. To use this approach, set the following 
parameters: Outbound_Proxy, Use_Outbound_Proxy, NAT_Keep_Alive_Dest, 
NAT_Keep_Alive_Msg, NAT_Keep_Alive_Intvl, and NAT_Keep_Alive_Enable. If the  
NAT_Keep_Alive_Msg parameter is set to blank, the PHONE ADAPTER will send a Carriage-
Return/Line-Feed as the Keep-Alive Message. 
 
The STUN approach works through more than 95% of home NATs when there is only a single 
PHONE ADAPTER in use behind the same NAT. The STUN approach requires a STUN server setup 
by the provider, but uses very few resources. The actual media flows directly between the PHONE 
ADAPTER and its peer. To configure STUN set the following parameters: STUN_Enable, 
STUN_Test_Enable, STUN_Server, NAT_Mapping_Enable, Substitute_VIA_Addr, 
NAT_Keep_Alive_Dest, NAT_Keep_Alive_Msg, NAT_Keep_Alive_Intvl, and 
NAT_Keep_Alive_Enable. 
 
 
The Manual Configuration approach requires coordinated administration of the NAT and the PHONE 
ADAPTER. It is not practical for general retail use, but can be used behind symmetric NATs 
occasionally found in larger businesses, for troubleshooting, and in circumstances where other 
mechanisms have been exhausted. The configure the PHONE ADAPTER for manual NAT traversal, 
set the EXT_IP parameter to the public/translated/outside/external IP address, the EXT_SIP_Port 
parameters (per line) to the translated port number for this line and PHONE ADAPTER, and the 
EXT_RTP_Port_Min parameter to the first translated port number reserved for this PHONE 
© 2004 Linksys Proprietary (See Copyright Notice on Page 2) 
 
 
 
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