Cisco ASA - Packet drops troubleshooting

[LovejitSingh1313]

Hello Experts @Rob Ingram  @balaji.bandi  

I have users complaining that Webex calls are dropping Even though they are getting 100+Mbps bandwidth on their PC's.  I am looking for commands which I can use to find the dropped packets and related reason for Particular IP.  

Thanks,

[balaji.bandi · Accepted solution]

check if sip inspect enabled ( so disable) default it enable

https://community.cisco.com/t5/security-documents/how-to-disable-sip-inspection-on-single-interface-of-pix-asa/ta-p/3127729

https://www.cisco.com/c/en/us/support/docs/security/asa-5500-x-series-next-generation-firewalls/113069-asa-disgi-enai-asdm-00.html

[LovejitSingh1313 · Accepted solution]

Hello @balaji.bandi 

The Firewall is ASA5506 with 9.9 OS running on it.  Sip, MGCP and http was disabled and I enabled it back to see the difference. 

The reason why i enabled it back because one of our client was having VoIP issues and got fixed by enabling SIP back.

Webex does not use Sip I believe. 

https://help.webex.com/en-us/WBX000028782/Network-Requirements-for-Webex-Teams-Services

Is there any way I can add custom ports into inspection engine.

Thanks,

[Rob Ingram]

Hi,
Real time traffic (Voip/Webex) is sensitive, could the outside interface link be intermittently congested?
Do you have SNMP monitoring on the outside interface to check usage?
Do you have QoS enabled to prioritise this traffic?

HTH

[LovejitSingh1313]

Same time when Webex calls are dropping user is getting 150 Mbps down / 20 up .  Even enabling MGCP, SIP does not help at all . I do not have any SNMP monitoring tool right now.  I see the packet drops at WAN interface, Recently I limit the WAN port to 500 Mbps to make it same as what we are getting from ISP.

Thanks @Rob Ingram 

[balaji.bandi]

we do run many ASA with webex / teams / sklype call never seen that behaviour as you mentioned.

we need more information in related to usage and latency and ping stuff.

have you tested bypass FW ?

[LovejitSingh1313]

Hello @balaji.bandi , 

I excluded all the following Protocols from inspection and setup bandwidth limit on internet inteface to make it same with ISP.

ctiqbe

h.323

mgcp

RTSP

SIP

SCCP

I will post you if this fixed the issue.

Thanks,

[balaji.bandi]

thanks for the input, let us know how it goes.

[LovejitSingh1313]

Hello @balaji.bandi  @Rob Ingram ,

Excluding all the Voice Protocols from Inspection engine and factory resetting the ISP modem fixed the issue.

Thanks alot