VoIP Phones - Cisco 7xxx: Difference between revisions
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<indicator name="VoIPConfiguring">[[File:menu-voip.svg|link=:Category:VoIP Phones|30px|Back up to the VoIP Configuring page]]</indicator>  | 
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[[file:Cisco7940.png||ALT=Cisco7940]]  | 
  [[file:Cisco7940.png||ALT=Cisco7940]]  | 
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==Phones and Versions Tested==  | 
  ==Phones and Versions Tested==  | 
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|3.8.6  | 
  |3.8.6  | 
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|7940G  | 
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|SIP41.8-5-4S  | 
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|Appears stable  | 
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|-  | 
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|7940G  | 
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|SIP41.9-4-2SR1-1S  | 
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|Phone runs sluggish, reboots randomly, not recommended  | 
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| ⚫ | |||
!colspan="2"|Feature Notes  | 
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|Supports [[VoIP no302|302 Redirect]]  | 
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|?  | 
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|Tested on FireBrick SIP Server  | 
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|Yes  | 
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|-  | 
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|IPv6 Support  | 
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|No  | 
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|}  | 
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'''* Important *'''  | 
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Whilst testing SIP41.8-5-4S it appears the phone/firmware is vulnerable to a SIP/UDP amplification attack where crafted SIP 'INVITE' packets sent on UDP 5600 cause the phone to respond to its upstream SIP gateway with multiple SIP 2.0 '404' packets. Measured at a rate of approximately 20 packets/second, whilst not a major cause for concern with a single phone could potentially cause service issues where several phones are in use.  | 
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This vulnerability is protected against by correct firewall protection/filtering limiting inbound UDP on SIP port 5600 to the phone to be exclusively from   | 
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the parent SIP service (e.g. voiceless.aa.net.uk - see the VoIP security/firewall section). '''It is not recommended to leave these phones connected to the internet without any protection.'''  | 
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==Firewall & Security==  | 
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*You will also want to set up firewall rules, as per the  [[VoIP Firewall]] page.  | 
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*Also see the [[VoIP Security]] page for information about securing your VoIP service.  | 
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[[Category:VoIP Phones|Cisco 7xxx]]  | 
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Latest revision as of 00:00, 15 March 2017
Phones and Versions Tested
| Cisco 7xxx Versions tested | ||
|---|---|---|
| Model | Version | Notes | 
| 7940 | 3.8.6 | 
 
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| 7940G | SIP41.8-5-4S | Appears stable
 
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| 7940G | SIP41.9-4-2SR1-1S | Phone runs sluggish, reboots randomly, not recommended | 
| Feature Notes | |
|---|---|
| Supports 302 Redirect | ? | 
| Tested on FireBrick SIP Server | Yes | 
| IPv6 Support | No | 
* Important *
Whilst testing SIP41.8-5-4S it appears the phone/firmware is vulnerable to a SIP/UDP amplification attack where crafted SIP 'INVITE' packets sent on UDP 5600 cause the phone to respond to its upstream SIP gateway with multiple SIP 2.0 '404' packets. Measured at a rate of approximately 20 packets/second, whilst not a major cause for concern with a single phone could potentially cause service issues where several phones are in use.
This vulnerability is protected against by correct firewall protection/filtering limiting inbound UDP on SIP port 5600 to the phone to be exclusively from the parent SIP service (e.g. voiceless.aa.net.uk - see the VoIP security/firewall section). It is not recommended to leave these phones connected to the internet without any protection.
Configuration
Firewall & Security
- You will also want to set up firewall rules, as per the VoIP Firewall page.
 - Also see the VoIP Security page for information about securing your VoIP service.
 
