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INVITE validation causing DNS lookup and hence delays - VVX Phones

SOLVED
robertrozario
Advisor

INVITE validation causing DNS lookup and hence delays - VVX Phones

Hi,

Ref :  "https://community.polycom.com/t5/VoIP-SIP-Phones/INVITE-vaidation-causing-DNS-lookups-delays/m-p/690..."

I am opening this post as the other post for this issue is saying resolved.

We are a service provider and we have experienced this issue on our VVX range handsets on various firmware from 4.1.x to 5.5.1 We have around 20K handsets in field. We use outbound proxy and cant register to serer directly hence cant use the solution mentioned in the other post.

Has anyone else experienced this issue. ?

Is it still ongoing.?

We use below config

<requestValidation
voIpProt.SIP.requestValidation.digest.realm=""
voIpProt.SIP.requestValidation.1.method="source"
voIpProt.SIP.requestValidation.1.request="INVITE"
/>

We see dns attempts and calls are delayed by 4 - 8 seconds.

when dns server becomes unreachable, we see this issue.

Regards

Robert

Message 1 of 7
1 ACCEPTED SOLUTION

Accepted Solutions
robertrozario
Advisor

Re: INVITE validation causing DNS lookup and hence delays - VVX Phones

If anyone is interested in this for a resolution, I raised via support and got below response.  Hope it helps some one. 

 

"

All is well when the DNS servers work fine. But when the dns server becomes unreachable, When the INVITE is sent, the phone sits there for 6 seconds, trying to resolve domain.com for NAPTR, SRV, and A records, against both of it's DNS servers, taking either 6 or 12 seconds, before it will finally respond.

[POLYCOM] That is an expected behavior. If you do not want phones to lookup DNS frequently you

can configure DNS cache using following parameters:

 

dns.cache.NAPTR.1.name="test.polycom.com"
dns.cache.NAPTR.1.order="1"
dns.cache.NAPTR.1.preference="1"
dns.cache.NAPTR.1.replacement="_sip._udp.test.polycom.com"
dns.cache.NAPTR.1.service="SIP+D2U"
dns.cache.NAPTR.1.ttl="3600"
dns.cache.SRV.1.name="_sip._udp.test.polycom.com"
dns.cache.SRV.1.port="5060"
dns.cache.SRV.1.priority="1"
dns.cache.SRV.1.target="test.polycom.com"
dns.cache.SRV.1.ttl="3600"
dns.cache.SRV.1.weight="1"
dns.cache.A.1.name="test.polycom.com"
dns.cache.A.1.address="10.10.10.10"
dns.cache.A.1.ttl="3600"


You can refer to https://support.polycom.com/content/dam/polycom-support/products/voice/business-media-phones/user/en... to understand DNS cache parameters(Refer page 440).
voIpProt.SIP.requestValidation.x.method1
source, digest, both,
-Null, no validation is made.
Otherwise this sets the type of validation performed for the request:
- source: ensure request is received from an IP address of a server belonging to the set of target registration servers;
What do the "set of target registration servers" mean? Where are the servers taken from? reg.X.server.X.address, voIpProt.server.X.address, or proxy address?

[POLYCOM] If you have configured reg.x.server.y.address means these are set of registration servers. If not configured, voIpProt.server.x are set of registration servers. When value of ‘source’ is set reg.x.server.y.address is checked first then reg.x.outboundProxy.address or voIpProt.SIP.outboundProxy.address.
Testing shows it will try to validate IPs from two parameters(whichever is defined):
• reg.x.server.* or reg.x.outboundProxy.address (even if voIpProt.SIP.outboundProxy.address defined)
• reg.x.server.* or voIpProt.SIP.outboundProxy.address(if reg.x.outboundProxy.address is not defined).
• voIpProt.server.x.address(used only when reg.x.server.y.address is not defined) or reg.x.outboundProxy.address.

So in conclusion the set of servers it checks the source against is: regXserver + proxy, so it will check against both and allow invites is there is a match on either.
As long as we have a regXserver set, Polycom will try to resolve it and compare source also against it. In case we do not want a DNS query, we have two choices: either set a DNS cache on phone, or not sert the reg.X.server."

 

Regards

 

Robert

View solution in original post

Message 5 of 7
6 REPLIES 6
SteffenBaierUK
Polycom Employee & Community Manager

Re: INVITE validation causing DNS lookup and hence delays - VVX Phones

Hello @robertrozario,

 

Please contact Polycom support as none of your mentioned Software Versions are currently supported.

 

Replied via a mobile device

----------------
The title Poly Employee & Community Manager is a community setting and does not reflect my role. I am just a simple volunteer in the community like everybody else. All posts and words are my own & do not represent the views of Employer.

----------------

Notice: This community forum is not an official Poly support resource, thus responses from Poly employees, partners, and customers alike are best-effort in attempts to share learned knowledge. If you need immediate and/or official assistance please open a service ticket through your proper support channels.
Please also ensure you always check the VoIP , Video Endpoint , Skype for Business , PSTN or RPM FAQ's
Message 2 of 7
robertrozario
Advisor

Re: INVITE validation causing DNS lookup and hence delays - VVX Phones

Hi Steffen,

This happened on the latest 5.7.1.2205 on a vVX400 and is still failing as below. 

This happens only when dns server doesnt responds/fails

 

|DNS server(s) marked unresponsive due to query loopcount exhaust or timeout[12]
000352.740|sip |3|00|NAPTR query for host 'xxxxxxxx.com' returned no results
000352.740|sip |3|00|CCallBase::IsTrusted : NAPTR lookup failed
000352.741|sip |4|00|doDnsListLookup(udp): doDnsSrvLookupForARecordList 'xxxxxxxx.com' found no records

 

Home Phone Information Phone Model VVX 400 Part Number 3111-46157-002 Rev:A MAC Address 00:04:F2:xx:xx:xx IP Mode IPv4 IP Address 192.168.1.116 UC Software Version 5.7.1.2205 Updater Version 5.9.1.1991

 

000352.741|sip |1|00|doDnsListLookup(udp): doDnsSrvLookupForARecordList for '1.1.1.1' port 5060 returned 1 results
000352.741|sip |1|00|doDnsListLookup(udp): result 0 '1.1.1.1' port 5060 isInBound 0
000352.741|sip |1|00|CCallBase::IsTrusted Source IP:1.1.1.1 and Server IP1.1.1.1
000352.743|sip |2|00|new UA Server INVITE trans state 'proceeding', timeout=0 (0x40eff508)
000352.743|sip |2|00|CStateInviteServer::CStateInviteServer() Entrance
Home
Phone Information
Phone Model	VVX 400
Part Number	3111-46157-002 Rev:A
MAC Address	00:04:F2:xx:xx:xx
IP Mode	IPv4
IP Address	192.168.1.116
UC Software Version	5.7.1.2205
Updater Version	5.9.1.1991

 

Regards

 

Robert

Message 3 of 7
SteffenBaierUK
Polycom Employee & Community Manager

Re: INVITE validation causing DNS lookup and hence delays - VVX Phones

Hello @robertrozario,

As explained this needs to come into support.

 

In order to raise a support ticket you need to work with your Polycom reseller as they need to do this for you.

End Customers are unable to open a ticket directly with Polycom support.

If this is some sort of an Internet discounter please post either your phone's MAC address or your Polycom devices serial so I can look up who would be able to support you. This may not be who you purchased the Polycom device from.

Please ensure to provide some feedback if this reply has helped you so other users can profit from your experience.

Best Regards

Steffen Baier

Polycom Global Services

----------------
The title Poly Employee & Community Manager is a community setting and does not reflect my role. I am just a simple volunteer in the community like everybody else. All posts and words are my own & do not represent the views of Employer.

----------------

Notice: This community forum is not an official Poly support resource, thus responses from Poly employees, partners, and customers alike are best-effort in attempts to share learned knowledge. If you need immediate and/or official assistance please open a service ticket through your proper support channels.
Please also ensure you always check the VoIP , Video Endpoint , Skype for Business , PSTN or RPM FAQ's
Message 4 of 7
robertrozario
Advisor

Re: INVITE validation causing DNS lookup and hence delays - VVX Phones

If anyone is interested in this for a resolution, I raised via support and got below response.  Hope it helps some one. 

 

"

All is well when the DNS servers work fine. But when the dns server becomes unreachable, When the INVITE is sent, the phone sits there for 6 seconds, trying to resolve domain.com for NAPTR, SRV, and A records, against both of it's DNS servers, taking either 6 or 12 seconds, before it will finally respond.

[POLYCOM] That is an expected behavior. If you do not want phones to lookup DNS frequently you

can configure DNS cache using following parameters:

 

dns.cache.NAPTR.1.name="test.polycom.com"
dns.cache.NAPTR.1.order="1"
dns.cache.NAPTR.1.preference="1"
dns.cache.NAPTR.1.replacement="_sip._udp.test.polycom.com"
dns.cache.NAPTR.1.service="SIP+D2U"
dns.cache.NAPTR.1.ttl="3600"
dns.cache.SRV.1.name="_sip._udp.test.polycom.com"
dns.cache.SRV.1.port="5060"
dns.cache.SRV.1.priority="1"
dns.cache.SRV.1.target="test.polycom.com"
dns.cache.SRV.1.ttl="3600"
dns.cache.SRV.1.weight="1"
dns.cache.A.1.name="test.polycom.com"
dns.cache.A.1.address="10.10.10.10"
dns.cache.A.1.ttl="3600"


You can refer to https://support.polycom.com/content/dam/polycom-support/products/voice/business-media-phones/user/en... to understand DNS cache parameters(Refer page 440).
voIpProt.SIP.requestValidation.x.method1
source, digest, both,
-Null, no validation is made.
Otherwise this sets the type of validation performed for the request:
- source: ensure request is received from an IP address of a server belonging to the set of target registration servers;
What do the "set of target registration servers" mean? Where are the servers taken from? reg.X.server.X.address, voIpProt.server.X.address, or proxy address?

[POLYCOM] If you have configured reg.x.server.y.address means these are set of registration servers. If not configured, voIpProt.server.x are set of registration servers. When value of ‘source’ is set reg.x.server.y.address is checked first then reg.x.outboundProxy.address or voIpProt.SIP.outboundProxy.address.
Testing shows it will try to validate IPs from two parameters(whichever is defined):
• reg.x.server.* or reg.x.outboundProxy.address (even if voIpProt.SIP.outboundProxy.address defined)
• reg.x.server.* or voIpProt.SIP.outboundProxy.address(if reg.x.outboundProxy.address is not defined).
• voIpProt.server.x.address(used only when reg.x.server.y.address is not defined) or reg.x.outboundProxy.address.

So in conclusion the set of servers it checks the source against is: regXserver + proxy, so it will check against both and allow invites is there is a match on either.
As long as we have a regXserver set, Polycom will try to resolve it and compare source also against it. In case we do not want a DNS query, we have two choices: either set a DNS cache on phone, or not sert the reg.X.server."

 

Regards

 

Robert

View solution in original post

Message 5 of 7
SteffenBaierUK
Polycom Employee & Community Manager

Re: INVITE validation causing DNS lookup and hence delays - VVX Phones

Hello @robertrozario,

 

welcome tback o the Polycom Community.


What was the Polycom reference usually starting with 1- just to close the loop?

Please ensure to provide some feedback if this reply has helped you so other users can profit from your experience.

Best Regards

Steffen Baier

Polycom Global Services

----------------
The title Poly Employee & Community Manager is a community setting and does not reflect my role. I am just a simple volunteer in the community like everybody else. All posts and words are my own & do not represent the views of Employer.

----------------

Notice: This community forum is not an official Poly support resource, thus responses from Poly employees, partners, and customers alike are best-effort in attempts to share learned knowledge. If you need immediate and/or official assistance please open a service ticket through your proper support channels.
Please also ensure you always check the VoIP , Video Endpoint , Skype for Business , PSTN or RPM FAQ's
Message 6 of 7
robertrozario
Advisor

Re: INVITE validation causing DNS lookup and hence delays - VVX Phones

Hi Steffen,

Unfortunately our distributor dont provide that detail. We raise a case with them and they raise it with Polycom .

Regards

Robert

Message 7 of 7