User guide

Developers guidelines | AT commands
200 June 2010
AT+CGTFT Traffic flow template
Description: Allows the TE to specify a Packet Filter for a Traffic Flow Template (TFT)
that is used in the GGSN for routing of downlink packets onto different
QoS flows towards the TE. The concept is further described in the 3GPP
TS 23.060. A TFT consists of from one to up to eight Packet Filters, each
identified by a unique <packet filter identifier>. A Packet Filter also has an
<evaluation precedence index> that is unique within all TFTs associated
with all PDP contexts that are associated with the same PDP address.
The set command specifies a Packet Filter that is to be added to the TFT
stored in the ME and used for the context identified by the (local) context
identification parameter, <cid>. The specified TFT will be stored in the
GGSN only at activation or MS-initiated modification of the related con-
text. Since this is the same parameter that is used in the AT+CGDCONT
and AT+CGDSCONT commands, the +CGTFT command is effectively an
extension to these commands. The Packet Filters consist of a number of
parameters, each of which may be set to a separate value.
A special form of the set command, +CGTFT= <cid> causes all of the
Packet Filters in the TFT for context number <cid> to become undefined.
At any time there may exist only one PDP context with no associated TFT
amongst all PDP contexts associated to one PDP address. At an attempt
to delete a TFT, which would violate this rule, an ERROR or +CME ERROR
response is returned.
The read command returns the current settings for all Packet Filters for
each defined context. In case no filter is defined the read command will
return “OK” only.
The test command returns values supported as a compound value. If the
MT supports several PDP types, the parameter value ranges for each PDP
type are returned on a separate line. TFTs will be used for PDP-type IP and
PPP only. For PDP-type PPP a TFT is applicable only when IP traffic is car-
ried over PPP. If PPP carries header-compressed IP packets, then a TFT
cannot be used.
Set command: AT+CGTFT=[<cid>, [<packet filter identifier>, <evaluation precedence
index> [,<source address and subnet mask> [,<protocol number (ipv4)/
next header (ipv6)> [,<destination port range> [,<source port range>
[,<ipsec security parameter index (spi)> [,<type of service (tos) (ipv4) and
mask/traffic class (ipv6) and mask> [,<flow label (ipv6)> ]]]]]]]]]>
Read command: AT+CGTFT? (Read the current general parameter settings)