GigaSMART GTP Whitelisting and GTP Flow Sampling

Required Licenses: GTP Filtering & Correlation and FlowVUE

Use GTP forward listing and GTP flow sampling to provide subsets of GTP correlated flows to tools. GTP forward listing selects specific subscribers based on IMSI, while GTP flow sampling uses map rules to select subscribers. Starting in software version 4.8, GigaSMART supports GTP overlap mapping, which combines both forward listing and flow sampling maps as part of a map group. Refer to GTP Overlap Flow Sampling Maps

Starting in software version 4.5, a GigaSMART group (gsgroup) associated with GTP applications can have multiple GigaSMART engine port members (e ports), up to four, forming an engine group. Refer to GTP Scaling.

Refer to the following sections:

GTP Whitelisting

GTP forward listing selects specific subscribers based on IMSI. The forward list contains up to 2,000,000 subscriber IMSIs. For subscribers in the forward list, 100% of their traffic is always sent to a specified tool port.

For example, when a subscriber session comes in, GTP forward listing checks the IMSI of the subscriber. If the incoming IMSI or RAN matches an IMSI or RAN in the forward list, the session is sent to the tool port or load balancing group specified in the forward list map.

Starting in software version 4.7, GTP forward listing is supported in a cluster. Refer to GTP Whitelisting in a Cluster for more information.

GTP Flow Sampling

GTP flow sampling samples a configured percentage of GTP sessions. GTP flow sampling uses map rules to select subscribers and then forward a percentage of the packets to tool ports.

Pass rules are defined in flow sampling maps. Each rule contains some combination of IMSI, IMEI, and MSISDN numbers or patterns, Evolved Packet Core (EPC) interface type, GTP version, Access Point Name (APN), or QoS Class Identifier (QCI), as well as a percentage to sample. The flow is sampled to see if it matches a rule. The percentage of the subscriber sessions matching each rule are selected.

Map rules specify the type of traffic to be flow sampled by that map. For each new session, map rules are evaluated in top-down order of decreasing priority. If there is a match, the indicated percentage of the subscriber session is either accepted or rejected. If accepted, the traffic is sent to the tool port or load balancing group specified in the map. If rejected, the traffic is dropped. If there is not a match to a rule, the traffic is passed to subsequent maps.

Starting in software version 4.6, GTP load balancing in a cluster is supported for GTP flow sampling. For an example of GTP load balancing in a cluster, refer to GigaSMART GTP Whitelisting and GTP Flow Sampling.

GTP Subscriber Aware Random Sampling

GTP Subscriber Aware Random Sampling allows to randomly sample all the subscriber’s IMSI on a rotational basis. Based on the configured sampling percentage, the selected sessions are either sampled in or out. The correlation engine takes the configurable interval as an input to rotate the random selection of each of the subscriber’s sessions.

The configurable interval is a minimum of 12 hours and a maximum of 48 hours. Each GigaSMART node must be synchronized with an NTP/PTP server, as UTC time is involved in the random selection of the subscriber’s sessions.

Note:  This feature is effective for a new subscriber’s sessions after enabling the random sampling.

The Map rules in the GTP random sampling are similar to GTP Flow Sampling. For more information refer to GigaSMART GTP Whitelisting and GTP Flow Sampling.

To enable GTP Random Sampling do the following:

1.   From the left navigation pane, go to System > GigaSMART > GigaSMART Groups.
2. Select a GigaSMART Group and click Edit.
3. Under GigaSMART Parameters, go to GTP and select GTP Random Sampling check box.
4. Enter the time in Rotation Interval in multiples of 12 hours.
5. Click OK.