GTP Overlap Flow Sampling for 4G and 5G

GTP Overlap Flow Sampling for 4G and 5G enables tools to receive their own copy of traffic, through independent evaluation of second level maps. In this overlap mode, if a packet matches a map rule, such as for tool A, that packet is still available to be matched again in subsequent maps, such as for tool B and tool C. The multiple copies of a GTP packet are sent to multiple destinations simultaneously. This applies to both GTP forward list selective forwarding - forward (formerly whitelist)ing and GTP flow sampling even if sampling is not employed.

The destination could be a single tool port, a GigaStream or an IMSI based load balanced tool port/GigaStream for a particular tool set. The GigaStream sends traffic to various links, connected to an external load balancer that would be connected to multiple tools.

Configure GTP Overlap Mapping

The configuration of GTP whitelisting and GTP flow sampling maps that are part of the GTP overlap flow sampling map group follow the same configuration considerations discussed previously in GigaSMART GTP Whitelisting and GTP Flow Sampling. As is the case with regular non-overlap GTP mapping, GTP forward listing selects specific subscribers based on IMSI, whereas GTP flow sampling uses map rules to select subscribers and then forward a percentage of the packets to tool ports.

Configuration Considerations

This section details certain configuration considerations that apply only to the configuration of GTP forward listing and flow sampling maps for GTP overlap flow sampling maps.

A second level type map specifying GTP overlap flow sampling map mode must be selected to configure GTP forward listing and flow sampling maps.

To configure a GTP whilelisting map in overlap flow sampling map mode, select Type as Second Level and Subtype as Flow Whitlelist Overlap in a map.

To configure a GTP flow sampling map in GTP overlap flow sampling map mode, select Type as Second Level and Subtype as Flow Sample Overlap in a map .

You can configure one GTP forward listing map and one GTP flow sampling map pair that contain traffic policies corresponding to one destination port group. The load balanced port groups can contain a single port, a port range, or a GigaStream. Note that port groups used in GTP overlapping maps support GigaStream.

The maximum number of port groups per single GTP overlap flow sampling map group is six.

For more information about port groups, refer to Port Groups.

Use the following sequence to help you determine the maximum number of port group members:

1.   Determine the number of members per port group and add 1 to the number.
2. Multiply each port group result times each other.
3. The total multiplication should not exceed 4096.

For instance, assume the following configuration in a GTP overlap mapping group:

■   Port Group 1—2 load balanced GigaStreams
■   Port Group 2—3 load balanced GigaStreams
■   Port Group 3—1 load balanced tool port
■   Port Group 4—1 load balanced GigaStream
■   Port Group 5—4 load balanced tool ports

The total number becomes:

(2+1)*(3+1)*(1+1)*(1+1)*(4+1) = 240

Since this does not exceed the maximum number of multicast IDs (4096), the tool configuration shown is accepted.

A GTP overlap flow sampling map pair consists of one GTP forward listing map and one GTP flow sampling map having the same destination port group. Within a GTP overlap flow sampling map pair the forward listing map rules are applied before the flow sampling map rules.

In GTP Overlap map configuration, the virtual port sending traffic to all the port groups needs to be configured in GTP overlap mode.

To configure the virtual port with GTP overlap mode, select GTP Overlap when configuring the virtual port.

To create a group of maps for GTP forward listing and GTP flow sampling, select Maps > Maps > Map Groups, and then click New. The maps for a map group are entered in the Maps field. All the maps in a map group receive traffic according to map rules, rather than map priority. Thus, multiple copies of a GTP packet can be sent to more than one tool.

The Maps field of the Map Group page groups the forward listing and flow sampling maps.

Keep in mind the following configuration considerations for map groups:

■   A map group can be associated with only one GigaSMART group (gsgroup).
■   All maps within a map group must be connected to the same vport.
■   A map group can consist of only one GTP whitelisting map or only one GTP flow sampling map but it cannot contains two maps of the same type.
■   Once a map group is created, it cannot be edited to change the type or subtype of the map. However, you can add and edit the map rules for a map while it is configured in a map group.

For more information about map groups, refer to Create Map Groups.

The GTP forward list is an IMSI list which is common to all whitelist maps. You can configure an optional rule within a whitelist map to specify a GTP version or interface-based policy.

Other than specifying a new second level type using Type Second Level and Subtype Flow Whitelist Overlap when creating the map, the configuration of GTP whitelist maps follows the same configuration guidelines as given in the section GTP Whitelisting.

A maximum of six whitelist maps sending traffic to six different port groups can be configured per GigaSMART group (gsgroup).

In GTP overlap flow sampling map mode, GTP flow sampling (rule-based flow sampling) is performed after GTP whitelist-based forwarding. Therefore, flow sampling maps have a lower priority than whitelist maps. Thus, within a GTP overlap map pair that consists of a single GTP forward list overlap map and a GTP flow sampling overlap map, the GTP whitelist map is of higher priority.

Within the flow sampling maps, the rules in the first map have a higher priority than the rules in the second, third, and subsequent maps. Within any single map, rules are evaluated in order.

A maximum of six flow sampling maps sending traffic to six different port groups can be configured per GigaSMART group (gsgroup).

Within each GTP forward listing and flow sampling pair, if there is not a match to an IMSI in the whitelist map, the traffic flow is sampled based on the rules in the flow sampling map. The flow sampling rules specify IMSI, IMEI, and MSISDN numbers, as well as the percentage to sample.

Within each map pair, packets are then accepted or rejected. Accepted packets are forwarded to the port groups for load balancing. Rejected packets are dropped.

Use the following steps to configure

Task

Description

UI Steps

1

Create GigaStreams that will be part of the port groups
  1. Select Ports > Port Groups > GigaStreams
  2. Click New.
  3. Enter the name in the Alias field.
  4. In the Ports field, select port.
  5. Click Save.
  6. Configure a second GigaStream with the alias, select the required ports in the Ports field, and click Save.

2

Create port groups and specify the tool ports and assign GigaStreams to the port groups. The port groups will also be load balanced.
  1. Select Ports > Port Groups > All Port Groups.
  2. Click New.
  3. Enter the name in the Alias field.
  4. Select Type GigaSMART Load Balancing.
  5. In the Ports field, select ports.
  6. In the GigaStream field, select the required GigaStream.
  7. Click Save.
  8. Configure a second Port Group. with the alias, select ports and in the Ports field, select GigaSMART Load Balancing, select in the GigaStream field, and then click Save.

3

Configure a GigaSMART group and associate it with a GigaSMART engine port.
  1. From the device view, select GigaSMART > GigaSMART Groups.
  2. Click New.
  3. Enter the name in the Alias field.
  4. In the Port List field, select an engine port.
  5. Click Save.

4.

Create a virtual port.

Note:  You must enable GTP Overlap when configuring a virtual port for GTP overlap mapping.
  1. From the device view, select GigaSMART > Virtual Ports > Virtual Ports.
  2. Click New
  3. Enter the name in the Alias field.
  4. In the GigaSMART Group field, select the group.
  5. Select GTP Overlap.
  6. Click Save.

5.

Create the GTP Whitelist
  1. From the device view, select GigaSMART > GTP Whitelist.
  2. Click New.
  3. Enter Whitelist in the Alias field
  4. Go to Task 6.

6.

Fetch whitelist files from a specified

location to populate the GTP forward list.
  1. On the GTP Whitelist page, select Bulk Upload.
  2. Select Bulk Entry Operation for IMSI Upload Type.
  3. Select Upload from URL from the Bulk Upload Type list.
  4. Enter the URL in the Enter Remote URL field.
  5. Click Save.

7.

Associate the GigaSMART group to the GTP forward list.
  1. From the device view, select GigaSMART > GigaSMART Groups > GigaSMART Groups
  2. Select GS Group GS31 created in Task 3 and click Edit
  3. Under GTP Whitelist, click on the GTP Whitelist Alias field and select Whitelist.
  4. Click Save.

8.

Configure the GigaSMART operation for GTP forward listing.
  1. From the device view, select GigaSMART > GigaSMART Operations (GSOP) > GigaSMART Operation.
  2. Click New.
  3. Enter the name in the Alias field.
  4. Select the GigaSMART Group from the GigaSMART Groups list.
  5. Select GTP Whitelist from the GigaSMART Operations (GSOP) list
  6. Select Load Balancing from the GigaSMART Operations (GSOP) list.
  7. Configure Load Balancing as follows:
  • Select Stateful
  • Set Type to GTP
  • Select Hashing
  • Select IMSI
  1. Click Save.

9.

Configure the GigaSMART operation for GTP flow sampling.
  1. From the device view, select GigaSMART > GigaSMART Operations (GSOP) > GigaSMART Operation.
  2. Click New.
  3. Enter the name in the Alias field.
  4. Select the GigaSMART Group from the GigaSMART Groups list.
  5. Select Flow Sampling-GTP.
  6. Select Load Balancing from the GigaSMART Operations (GSOP) list.
  7. Configure Load Balancing as follows:
  • Select Stateful
  • Set Type to GTP
  • Select Hashing
  • Select IMSI
  1. Click Save.

10.

Configure the first level maps.

In the rules, 2123 is GTP-c traffic and 2152 is GTP-u traffic.
  1. Configure the first map as follows:
  • Alias.
  • Type and Subtype
  • Source
  • Destination
  • Rule 1
  • Rule 2
  • Click Save.

11.

Configure the first second level GTP overlap map for GTP forward listing If there is a match to an IMSI in the forward list for GTP version 1 traffic, it is then forwarded to load balancing port group.
  1. Select Maps > Maps > Maps.
  2. Click New.
  3. Configure the map.
  • Alias
  • Type and Subtype
  • Source
  • Destination
  • GSOP
  • Rule 1.
  1. Click Save.

12.

Configure a second level map for GTP flow sampling, the flow sampling map. If there is not a match to an IMSI in the forward list, the traffic flow is sampled based on the rules in this map. Accepted packets are forwarded to load balancing port group.
  1. Select Maps > Maps > Maps.
  2. Click New.
  3. Configure the map.
  • Alias
  • Type and Subtype.
  • Source.
  • Destination
  • GSOP
  • Rule 1
  1. Click Save.

13.

Configure the next second level GTP overlap map for GTP forward listing If there is a match to an IMSI in the forward list for GTP version 2 traffic, it is then forwarded to load balancing port group.
  1. Select Maps > Maps > Maps.
  2. Click New.
  3. Configure the map.
  • Alias
  • Type and Subtype
  • Source
  • Destination
  • GSOP
  • Rule 1
  1. Click Save.

14.

Configure the next second level map for GTP flow sampling. If there is not a match to an IMSI in the forward list as evaluated by the second level GTP whitelisting map WLMAP2, the traffic flow is sampled based on the rules in this map. Accepted packets are forwarded to load balancing port group.
  1. Select Maps > Maps > Maps.
  2. Click New.
  3. Configure the map:
  • Alias
  • Type and Subtype: Sample Overlap
  • Source
  • Destination
  • Rule 1
  1. Click Save.

15.

Configure a map group. Add the GTP

forward listing and the two GTP flow

sampling maps configured in previous

steps.
  1. Select Maps > Map Groups.
  2. Click New.
  3. Enter OverlapMap in the Alias field.
  4. In the Maps field, select the maps.
  5. Click Save.

Overlap maps are displayed based on the following:

■   If at least 1 flow-sample map accepts the packets among all the pairs of overlap maps, the Sample (Tx) counters in the GTP Interface stats will be incremented. If more than 1 pair of maps accepts the packets, the Sample (Tx) counters in the GTP Interface stats is incremented only once.
■   If at least 1 whitelist map matches the packets among all the pairs of overlap maps, the Sample (Tx) counters in the GTP Interface stats will be incremented. If more than 1 pair of maps matches the packets, the Sample (Tx) counters in the GTP Interface stats is incremented only once.
■   If there are no WL maps and all flow sample maps are no rule match, then Sample(Tx) and Sample Out counters in the GTP Interface stats is not incremented.