Knowledgebase

 
 
Knowledgebase Article
Knowledgebase > Unified Communications > SmartNode > SmartWare


Why am getting a "503 Service Unavailable” SIP message when sending a SIP call to the SN?
Article Id #: 454

One of the main reasons for this is that the SmartNode does not allow for any "untrusted" host IP Addresses to pass through whenever the "trust" command is configured in the SIP interface.

 

Managing trusted hosts:

A list of trusted remote peers can be configured on SIP interfaces. If configured, only connections with peers in that list will be accepted. The list may contain IP-addresses or FQDNs or "remote".  If no trusted peers are configured all connections are accepted.

The SmartNode responds with a SIP "503 Service Unavailable” to requests received from hosts which are not trusted. 

interface sip IF_SIP
bind context sip-gateway GW_SIP
route call dest-interface IF_FXO
remote 10.10.10.10 5060
local 10.10.10.10 5060
trust remote

In the example above, only requests coming from the IP address 10.10.10.10 will be accepted.  Anything else will receive the "503 Service Unavailable" from the SmartNode.

 

In some cases, it is desirable not to send an answer back to an untrusted SIP host. For those cases, in the context sip-gateway, this behavior can be changed. By default the SmartNode responds with a “503 Service Unavailable” to SIP requests received from hosts which are not trusted. With the [no] form of the command below, the SmartNode will not send any message to untrusted hosts.

[node](sip-gw)[name]# [no] answer-untrusted-hosts

context sip-gateway GW_SIP_0

interface LAN
bind interface IF_IP_LAN context router port 5060

context sip-gateway GW_SIP_0
bind location-service LOC_SVC
no answer-untrusted-hosts
no shutdown

The SmartNode will no longer respond to untrusted hosts when the "no answer-untrusted-hosts" command is configured.

 

User Rating
This answer was helpful This answer was not helpful (8786 vote(s)) 
User Comments  Add a Comment )

 
 
Products
Unified Communications
> VoIP Adapters
> Fax Adapters
> VoIP Gateways
> VoIP Routers
> VoIP IADs - Integrated Access Devices
> Enterprise Session Border Controllers
> Media Gateways
> SS7 Gateways
> Secure End Points (SIP Phones)
> VoIP Public Address & Mass Notification
Software and Cloud
> Virtual SBC | Virtualized SBC
> Virtual Access Router
> VPN Server
> IPv6 IPv4 Converter
> Intelligent Edge Orchestration
> NFV & SDN
Networking & Access
> Ethernet Extenders
> Industrial Switches
> Industrial Ethernet
> Unmanaged Industrial Ethernet Switches
> Managed Industrial Ethernet Switches
> Industrial PoE Switches
> PoE Extenders
> Industrial Network Solutions
> xDSL Products | DSL Modems, DSL VoIP, DSL Router Modems
> Routers
> Dial-Up Access

Sunset Products
 
Datacom Industrial Connectivity
> Industrial PoE Products
> Ethernet Over Fiber
> Line Drivers / Short Range Modems
> Wireline Analog Modems
> Pro AV Live & Media Broadcast Systems
> Fiber Serial DataCom (RS-232/422/530/188C)
> Fiber Telecom (T1/E1/PRI, Analog & ISDN)
> Multiplexers & Sharing Devices
> SFP (Small Form Pluggable) Modules and Kits
> Fiber Alarming, Notification, Relay & Control
> Other Network Extenders
> Defense/Security Fiber Communications
> Baluns
> Surge Protectors & Opto-Isolators
> DataTaps, Testers, Adapters, Rack Kits
> Interface Converters
> Fiber Rack & Enclosure Systems
> Fiber Repeaters & Wavelength Division Multiplexers (WDM)
> Waveguide RF Filters
Media Transport
> Artel Racks & Chassis Infrastructure
> Video Over IP Transport
> Video Over Fiber Transport
> Video, Audio & Data Over Fiber Transport
> Video & Audio Over Fiber Transport
> Ethernet Over Fiber Transport
> Serial DataComm Over Fiber Transport
> Video, Fiber Testers & Splitters
> Wave Division Multiplexers
> Ethernet Switches
> SFP Modules and Kits
 
Sales: [email protected] / +1 301 975 1000
Support: [email protected] / +1 301 975 1007
Join Our Email List
Have Us Contact You
or
Login Connect With Us
X Linkedin Facebook Youtube
 
     Patton LLC Copyright © 2025 All Rights Reserved.

|  Sitemap  |   Legal  |   Privacy Policy  |   Disclaimer  |    X  Facebook  YouTube  LinkedIn  RSS