FortiGate
FortiGate Next Generation Firewall utilizes purpose-built security processors and threat intelligence security services from FortiGuard labs to deliver top-rated protection and high performance, including encrypted traffic.
gmanea
Staff
Staff

Description

This article explains how to confirm if SIP traffic is being handled by SIP ALG or by SIP Session Helper.


Solution
By default, FortiGate is using SIP ALG to process SIP traffic.

To verify it checking configuration and counters:

FortiGate # show full system setting | grep default-voip-alg-mode
#set default-voip-alg-mode proxy-based

Proxy-based         <----- Default SIP ALG mode.
Kernel-helper-based <----– SIP session helper.

To verify counters based on the mode:

1) If SIP Sessions Helper is handling the SIP traffic, the command below will display counters:

FortiGate # diag sys sip status
dialogs: max=131072, used=0
mappings: used=0
dialog hash by ID: size=8192, used=0, depth=0
dialog hash by RTP: size=8192, used=0, depth=0
mapping hash: size=8192, used=0, depth=0
count0: 0
count1: 2
count2: 10
count3: 0
count4: 0

2) If SIP ALG is handling the SIP traffic, the command below will display counters:

FortiGate # diag sys sip-proxy stat
sip stats

vdom name: root
---------------------------
     active-sessions: 1
     calls-attempted: 57
     calls-established: 27
     calls-failed: 30

     calls-active: 0
     registers-active: 1
              |     received  |     blocked   |  unknown form |  long headers
     req-type |    req    resp|    req    resp|    req    resp|    req    resp
     UNKNOWN         0   47227       0   47227       0   47227       0       0
     ACK            86       0       0       0       0       0       0       0
     BYE            27      27       0       0       0       0       0       0
     CANCEL         14      14       0       0       0       0       0       0
     INFO            0       0       0       0       0       0       0       0
     INVITE        107     223       0       0       0       0       0       0
     MESSAGE         0       0       0       0       0       0       0       0
     NOTIFY       5789    5788       0       0       0       0       0       0
     OPTIONS         0       0       0       0       0       0       0       0
     PRACK           0       0       0       0       0       0       0       0
     PUBLISH     10371     802       0       1       0       0       0       0
     REFER           2       2       0       0       0       0       0       0
     REGISTER   100678   81543      25       0      25       0       0       0
     SUBSCRIBE   19857   13333       0       2       0       0       0       0
     UPDATE          0       0       0       0       0       0       0       0
     PING            0       0       0       0       0       0       0       0

Related links.
https://docs.fortinet.com/document/fortigate/6.4.5/administration-guide/858887/voip-solutions
https://docs.fortinet.com/document/fortigate/6.2.7/cookbook/858887/voip-solutions
https://pub.kb.fortinet.com/ksmcontent/Fortinet-Public/current/FortiGate_6_0/fortigate-sip-603.pdf
https://kb.fortinet.com/kb/documentLink.do?popup=true&externalID=fortigate-voip-sip-521pdf

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