What’s New in FortiOS 5.6 for FortiCarrier

What’s New in FortiOS 5.6

New features added in 5.6.1

GTP enhancement and GTP Performance Improvement. (423332)

The GTP changes in 5.6.1 take place in the following categories:

New GTP features and functionality enhancements.

  • GTP message filter enhancements, including: l Unknown message white list l GTPv1 and GTPv2 profile separation l Message adoption.
  • GTP IE white list.
  • Global APN rate limit, including: l sending back REJECT message with back-off timer l “APN congestion” cause value
  • GTP half-open, half-close configurable timer.

GTP performance improvements.

  • Implemented RCU on GTP-U running path. i.e, no locking needed to look up tunnel state when processing GTP-U.

Note the RCU is only applied on GTPv1 and GTPv2 tunnels. It is not used for GTPv0 tunnels, due to the fact that (1) GTPv0 traffic is relatively minor compared with GTPv1 and GTPv2, and (2) GTPv0 tunnel indexing is totally different from GTPv1 and GTPv2. GTPv0 tunnel is indexed by [IMSI, NSAPI]. GTPv1 and GTPv2 tunnel is indexed by [IP, TEID]

  • Localized CPU memory usage on GTP-U running path.
  • GTP-C: changed some GTP tables from RB tree to hash table, including l GTP request tables, and GTPv0 tunnel tables. l Testing showed, when handling millions of entries adding/deleting, hash table performance was much better.
  • 3.2 Hash table is compatible with RCU API, so we can apply RCU on these GTP-C tables later for further performance improvements.
  • GTP-C, improved GTP path management logic, so that GTP path will time out sooner when there are no tunnels linked to it

CLI Changes:

New Diagnose commands: diagnose firewall gtp

New features added in 5.6.1                                                                                            What’s New in FortiOS 5.6

Option Description
hash-stat-tunnel GTP tunnel hash statistics.
hash-stat-v0tunnel GTPv0 tunnel hash statistics.
hash-stat-path GTP path hash statistics.
hash-stat-req GTP request hash statistics.
vd-apn-shaper APN shaper on VDOM level.
ie-white-list-v0v1 IE white list for GTPv0 or v1.
ie-white-list-v2 IE white list for GTPv2.

diagnose firewall gtp vd-apn-shaper

Option Description
list List

diagnose firewall gtp ie-white-list-v0v1

Option Description
list List

diagnose firewall gtp ie-white-list-v2

Option Description
list List

config gtp apn-shaperapn-shaper

Option Description
apn APN to match. Leave empty to match ANY.

“apn” field can be empty, it matches ANY apn. when configured, it is used to set a limit for any apn which is not explicitly listed; Also, if configured, such an entry should be the last entry, as it is first-match rule.

rate-limit Rate limit in packets/s (0 – 1000000, 0 means unlimited).

What’s New in FortiOS 5.6                                                                                            New features added in 5.6.1

Option Description
action Action. [drop | reject]

There is no back-off timer in GTPv0, therefor the reject action is not available for V0

back-off-time Back off time in seconds (10 – 360).

back-off-time visible when action is


Changed commands:

Under command firewall gtp, config message-filter is replaced by set message-filterv0v1


config firewall gtp edit <name> set message-filter-v0v1

New fields have been added to the config firewall gtp command context

Option Description
half-open-timeout Half-open tunnel timeout (in seconds).
half-close-timeout Half-close tunnel timeout (in seconds).


config firewall gtp edit <name> set half-open-timeout 10 set half-close-timeout 10 Models affected by change

l FortiGate 3700D l FortiGate 3700DX l FortiGate 3800D Overview   Overview of FortiOS Carrier features

Having trouble configuring your Fortinet hardware or have some questions you need answered? Ask your questions in the comments below!!! Want someone else to deal with it for you? Get some consulting from Fortinet GURU!

Leave a Reply

Name *
Email *

This site uses Akismet to reduce spam. Learn how your comment data is processed.