VPN High Latency

The only thing that crossed my mind is " what if IPsec traffic is not accelerated on the remote FGTs?" . You can check that easily from the CLI.

Yes the following cmd show soft vrs hardware process FG100C3G08338342 # get vpn ipsec stats crypto IPsec crypto devices in use: CP6 (encrypted/decrypted): null: 0 0 des: 0 0 3des: 11095399 5680328 aes: 2190 2190 CP6 (generated/validated): null: 0 0 md5: 0 0 sha1: 11097589 5682518 sha256: 0 0 4: 0 0 5: 0 0 SOFTWARE (encrypted/decrypted): null: 0 0 des: 0 0 3des: 0 0 aes: 0 0 SOFTWARE (generated/validated): null: 0 0 md5: 0 0 sha1: 0 0 sha256: 0 0 4: 0 0 5: 0 0 Unless you disable it from the vpn config, the FGT110 should process these via the CP6 ASIC. btw this is 4.3p17 on a FGT110C with approx 7 active tunnels or more get vpn ipsec stats tunnel tunnels total: 8 static/ddns: 8 dynamic: 0 manual: 0 errors: 1 selectors total: 12 up: 7

Okay nothing is kicked up to the CP6 and my bad the NPU offloading is not available in a FGT110C. So you can rule out any thing handle within software per-se.