Getting Started

Getting Started with Traffic Generation & Analysis

This section is designed to help you begin using XenaManager to set up a simple bi-directional layer-2 Ethernet switching test scenario.

Add Chassis

A testbed is essentially a set of ports that you are actively utilizing. Certain panels within XenaManager will exclusively display data for ports that are part of your ongoing testbed. This encompasses both the Port Configuration Grid, Stream Configuration Grid, as well as Global Statistics.

1. Press the Add Chassis button located to the left in the ribbon bar at the top of the application.

Fig. 1 Add chassis

2. Fill in the IP address or hostname of the chassis, optionally change the Chassis Port Number, enter the password (default is xena) and click OK button. The Available Resources tree view at the left will now populate with the modules and ports contained in the chassis.

Fig. 2 Enter IP address, port number and password to add chassis

3. A new configuration has been created automatically when you start the application for the first time. This configuration contains a single default testbed called Default Testbed. You can see this testbed at the top of the resource tree view. You can create any number of testbeds but for now we will use the default testbed to start with.

4. Use Options ‣ Set Username to indicate who owns the port reservation.

Fig. 3 Set username

5. You can now add ports to your testbed. This is done by clicking the checkbox in the Used column to the right of the port name in the resource tree. Add two ports to your testbed in this way. Please ensure that the two ports are connected through a standard layer-2 switch. 5. If you only want to see the ports included in your testbed you can click the Show Only Used Ports checkbox in the testbed selection part of the resource tree. 6. To quickly reserve all ports in your testbed click the Reserve Used Ports button next to the Show Only Used Ports checkbox.

Configure Module

1. Reserve a module, and go to Resource Properties ‣ Main Module Config to configure module media configuration and port configuration.

Fig. 4 Module media configuration and port configuration

2. Configure the required clock configuration from Resource Properties ‣ Time & Clock Configuration

Fig. 5 Module media configuration and port configuration

Note

Note that ports are not automatically reserved just because you have included them in your testbed.

Add Port

1. Select the port(s) you want to use.

Fig. 6 Select ports

2. Click Reserve Used Ports, check Show Only Used Ports

Fig. 7 Reserve used ports and show only used ports

Configure Port

Select the port(s) to configure and click Resource Properties tab. Configure the following port parameters to accommodate your test.

Fig. 8 Configure ports

1. Min. Average Inter-Frame Gap

• Set to 20 –> 12B (Minimum allowed by Ethernet at 100% load) +8B Preamble

• Can be set to 16B to achieve >100% load for port pressure testing

• Values range between 16B to 20B depending on module.

2. MAC Address

• Used as default SRC.MAC for each stream

• Used when sending Ping or replying to ARP

3. MAC Auto-Training

• Used to train DUT with Xena MAC so stream won’t be flooded

4. React to PAUSE Frames

• This means enable Flow Control on this port

5. Gap Monitor

• Used to monitor(time) the disruptions of service to traffic

• Gap Monitor Start: After how many µs would the Monitor start

• Gap Monitor Stop: After how many packets would Monitor stop

• Results can be seen in port statistics (type of GAP can only be set)

6. Payload Checksum Offset

• Used to enter a Headers + Payload Data Integrity Checksum

• Should start from offset 14 for pure L2 packets

• Should start after IP offset for L3 and beyond packets (because of TTL)

7. Max. Stream Header Length

• When user wants to set headers larger than 128

• Number of streams will be downsized to 1/2

8. Loopback Mode

• Off: Traffic flows naturally out of the port

• L1 RX to TX: Any received packet is bounced back through TX

• L2 RX to TX: Same as 8.2 yet it also swaps MAC SRC<>DST

• L3 RX to TX: Same as 8.3 yet it also swaps IP SRC<>DST

• TX(on) to RX: Packet goes out of TX but also internally direct to RX

• TX(off) to RX: Packet goes directly to RX (No link sync needed)

• Port to port: Any received packet goes out through the neighbor port

Fig. 9 Loopback mode

9. Latency offset

• Used to automatically eliminate transceiver + cable latency

• Set either manually or via Port Statistics calibrate button

10. IPv4

• Address/Subnet/Gateway used for PING and ARP functionality

11. Reply to ARP/PING Requests

• Enable port’s ability to reply to incoming ARP/PINGrequests

12. ARP and PINGv4 address Wildcard:

• Used to enable multi unique ARP/PING requests

Fig. 10 IP settings

Some module supports the following.

13. Port Impairment

• Link Flap: Set Duration, Repeat Period and Repetitions (0=continuous)

• PMA Errors: Set BER coeff and BER exp for the error insertion

14. Payload Mode

• Extended Payload

• Custom Data Field

Fig. 11 Configure port impairment

See also

See application note Freely Programmable Test Packets (Custom Data Fields) for details.

Add Stream

1. To add a stream, click Edit Menu ‣ Add Stream or right-click port and choose Add Stream, to add multiple streams select the Add Multiple Streams option.

Fig. 12 Add stream

2. Copy Stream feature can also be used when user right clicks on any stream and then select copy stream and paste it anywhere.

Fig. 13 Copy stream

Configure Stream

Select the new stream on the first port and ensure that you have selected the Resource Properties panel. The panel will now display the properties for the stream.

1. Insert test payload, TID: This is the stream ID used to identify Latency/Jitter/Packet Loss.

2. Description: Stream Description text (e.g. “Upstream connected to DUT Port 11”)

3. Stream State

• Disabled: Stream is not started when traffic is ON nor is it included in port rate usage.

• Suppressed: Stream is not started when traffic is ON, but it is included in port rate usage. (“Paused State”) can be switched to enabled on the fly.

• Enabled: Stream is started when traffic is ON.

4. Stop After: Send specific number of packets and stop traffic. Also used in sequential mode as stream packet quantity.

5. Stream Transmission Profile:

• Percent is L1 rate including IFG + Preamble.

• Configuring on field actually changes all the others accordingly.

• Grayed text can be edited. To have it set you need one more click.

6. Burst used to configure bursty traffic. Density sets the inner IFG inside the burst. There is a trade-off between the stream rate and the Burst rate.

Fig. 14 Burst profile

7. Error Injection: Can send specific errors on the fly - but only when traffic is ON.

8. Insert Frame Checksum, FCS: Unchecking this checkbox will cause error frames.

9. Packet Length:

• Fixed - for min value =x all packets will be x

• Incrementing - for min value =100 and max value=200 e.g. 100, 101, 102, 103, … ,197, 198, 199, 200, 100, 101, 102

• Butterfly - for min=100 max=200 e.g. 100, 200, 101, 199, 102, 198, 103, 197, 104, 196, 105 …

• Random - random values between min. and max.

• Mix - sends internet mixture of packet sizes. For some modules 4 packet sizes are programmable. If not supported the programming boxes are dimmed.

Fig. 15 MIX Weights sets can be loaded saved via the port resource properties

10. Payload Type:

• Incrementing 8-bits - means 00 01 02 03 04 05 … Provides built in payload integrity check for payload.

• PRBS-31 - provides Pseudo Random Bit Sequence of 2^31-1 pattern. Payload integrity error detection requires non-zero Payload Checksum Offset in port properties of both TX and RX ports.

• Random - provides Random bit Sequence pattern. Payload integrity error detection requires non-zero Payload Checksum Offset in port properties of both TX and RX ports.

• Pattern - you can set your own custom pattern. Payload integrity error detection requires non-zero Payload Checksum Offset in port properties of both TX and RX ports.

• Decrementing 8-bit: means FF FE FD FC FB FA … Payload integrity error detection requires non-zero Payload Checksum Offset in port properties of both TX and RX ports.

• Incrementing 16-bit: means 00 00 00 01 00 02 00 03 00 04 00 05 … Payload integrity error detection requires non-zero Payload Checksum Offset in port properties of both TX and RX ports.

• Decrementing 16-bit: means FF FF FF FE FF FD FF FC FF FB FF FA… Payload integrity error detection requires non-zero Payload Checksum Offset in port properties of both TX and RX ports.

Important

When using Incrementing 16-bit or Decrementing 16-bit, you need to check the option Payload Start From 0 to have the payload 00 00 00 01 00 02 00 03 00 04 00 05 … or FF FF FF FE FF FD FF FC FF FB FF FA….

11. Scroll down to the Packet Header Definitions section in the stream properties view. Here you will find a Wireshark-like protocol header editor which allows you to define the protocol headers for the stream. Expand the Ethernet segment to view the fields in the segment.

Fig. 16 Packet header definition

Note

Note that the Src MAC Address field has been automatically set to the MAC address of the containing port. Expand the dropdown-box in the Named Values column for the Dst MAC Address and locate the other port in your testbed. Note that the Raw Value column is also automatically updated with the MAC address of the peer port.

Set Up Simple Bidirectional Traffic

1. Add 1 stream for each traffic port (right-click and select Add Stream)

2. Select both streams using the Available Resources panel and CTRL.

Fig. 17 Pairing streams

3. Clicking Pair Streams results in:

Fig. 18 Streams paired

Stream Scheduler

The Stream Scheduler can be used to build a series of actions (operations) based on existing streams in the current testbed.

Before starting the Stream Scheduler, you must reserve ports and configure ports and streams. Example: 120 times the traffic is running for 5 seconds and then stopped for 5 seconds:

Fig. 19 Stream scheduler

Filters

Filters are used in order to get statistics on specific types of packets either specific content or specific packet size.

Note

These filters can also trigger the Capture mechanism or focus Histogram results.

Fig. 20 Port filters

1. Add match term - click to add new match term. Added to provided Statistics for a matched packet (e.g. Packets of VLAN 100)

2. Click to access the field you want to match (headers must be added manually per match term).

3. Position is set to beginning of field e.g. if you want to match last octet of IP, the offset should be incremented manually. Mask - to focus on a specific Byte the other should be set to 00

4. Value - The value you would like to match (the value is in Hex so 50Dec = 32Hex)

5. Length term - used to find specific packet sizes

6. Add filter - click to add/build a new filter based on match terms

7. Enable - checkbox to enable a filter to be present in the results and capture trigger

8. Describe - Name of the filter

Note

Filter Condition - Build a filter based on pre built terms using the &, |, and ~ operators.

Filter results under Global Statistics ‣ Port Statistics

Capture

1. Checkbox enabled means when click Start/Stop in global view, capture mechanism will Start/Stop on this port.

2. Start Triggers

• From ON: Means Automatically Start

• From FCS error: First FCS error seen triggers Capture Start

• From payload error: First Payload error seen triggers Capture Start

• Filter: First packet answering Filter condition triggers Capture Start

3. Stop Triggers

• Until full: Means Automatically stop when buffer full

• Until FCS error: First(/2nd) FCS error seen triggers Stop

• Until payload error: First(/2nd)Payload error seen triggers Stop

• Filter: First (/2nd) packet: answering Filter condition triggers Stop

• Until User Stop: Capture will keep capturing FILO till manually stopped.

4. Which packets to keep (which will be left in capture buffer)

• All: All packets are captured

• With FCS error: Only FCS error frames

• With payload error: Only payload error frames

• Without test payload: Only non stream packets remain

• With test payload: keeps only packets that are part of stream x(5) fill in the payload ID

• Filter: keeps only packets answering Filter X conditions

5. Test payload ID to capture

6. Bytes to keep in capture buffer.

7. Save capture buffer as PCAP file.

8. Open Capture buffer with Wireshark

Histogram

Histograms are used to plot different distributions of values gathered over time e.g.

• Tx/Rx Length (Packet size)

• Rx Latency (Latency and Jitter may drift over time)

• Rx Jitter

• Rx IFG (an additional way of observing Jitter behavior)

1. Add histogram - Multiple histograms can be run simultaneously.

2. Start Histogram - Start Manually or use checkbox to start from Global

3. Select the type of measurement you would like to track using the histogram.

4. Select which packets will be monitored by this histogram, either specific TID or packets answering a specific filter.

5. X-axis range choose the minimum offset and the resolution (step)

6. Use the Freeze button to freeze the view and enable the Save option.

Global Statistics

1. Go to the Global Statistics panel. You should now see your two test ports in the testbed in a grid view.

2. Press the Clear Counters button in the toolbar at the top of the panel to ensure that you start with a clean view.

3. Press the Start Traffic button to start traffic on all test ports in your testbed. You should now see the TX and RX traffic counters start to increment for both ports.

4. Press the Stop Traffic button to stop the traffic on both ports.

Note

The Global Statistics view will exclusively display ports and streams utilized by your current testbed. If you need to briefly examine the statistics counters for a different port, you can utilize the single-resource Port Statistics panel. This panel will provide statistics for the currently selected port, regardless of whether it is part of your testbed or not.

Fig. 21 Global statistics - port statistics

Fig. 22 Global statistics - stream statistics

Note

(TX-RX) packets gives packet loss results based on TX packets and RX packets.

RX packets can consist of two parts: RX_1 originated from the TX port, RX_2 duplicated by the DUT

1. (TX-RX) > 0:

   1. TX > RX_1+RX_2. Transmitted packets more than received even if there is duplication from the DUT.

2. (TX-RX) = 0:

   1. TX-RX_1 = 0, and RX_2 = 0. All transmitted packets are correctly received, and there is no duplication introduced by the DUT.

   2. TX-RX_1 = d, but RX_2 = d. Some transmitted packets are not received but the duplications by DUT cancels out the difference, where d is positive.

3. (TX-RX) < 0:

   1. TX-RX_1 = 0, RX_2 > 0. There is duplication from the DUT.

   2. TX-RX_1 = d, RX_2 > d. Duplication from the DUT is large than the lost, where d is positive

Lost Packets

Given that RX can consist of two parts as mentioned above, we cannot be certain about the TX-RX_1. Consequently, we need use the sequence numbers in the packets to calculate “the holes in the sequence”. For example, when the TX sends #0,#1,#2,#3,#4,#5,#6, but #3 is not received by the RX, then TX-RX_1 = 1. But if #3 is not truly lost but is delayed by the DUT and later received by the RX, the TX-RX_1 will be back to 0.

TX: #0,#1,#2,#3,#4,#5,#6 RX: #0,#1,#2,#4,#5,#6 (Lost Packets = 1) (after a while…) RX: #3 (Lost Packets = 0)

Unfortunately, there is no one mechanism that can handle both scenarios at the moment.

Logging and Reporting

Enable Counter Logging - in order to save results over time and record all results for each second that passes. Enable Generate Report - in order to generate a report of accumulated results.

Click Select Types, and select the counters you want to record and/or include in the report

Statistics Charting

Click Add Chart and select the chart types you want. Then click Start Charting.

Getting Started with Network Impairment

This section is intended to guide you in using XenaManager to initiate a basic traffic impairment scenario for network impairment.

Configure Chimera Module

1. Description: In this field add a Module Description text

2. Port Configuration: Choose the port speed

Fig. 23 Configure chimera module

Add Chimera Port

1. Select the port(s) you want to use.

2. Click Reserve Used Ports, check Show Only Used Ports

Fig. 24 Reserve ports

Enable Impairment

You need to enable impairment on the ingress port, where the traffic enters.

1. Click port

2. Go to Impairment Config tab.

3. Enable Enable Impairment. When you observe a green wave icon alongside the in-sync indicator, it indicates that the port is capable of performing impairments.

Fig. 25 Enable impairment on port

Configure Flow Filter

Let’s set up a flow to capture all frames containing a single VLAN tag with a value of 10. Here’s how you can configure it.

1. Expand a port and select Flow (1).

2. Change flow description to VLAN 10. This helps you to identify the flow later.

3. Enable the filter. This sets the filter in action.

4. Choose 1 VLAN Tag for Layer 2+.

5. Check Tag and enter 10 in Value.

6. Click Apply to apply the changes.

Fig. 26 Configure flow filter

Configure Flow Impairments

Now that we have a filter in place to capture all frames with a single VLAN tag carrying the value 10, we can proceed to discard 20 packets every 0.1 second from the filtered frames using the Drop function..

1. Select Impairment Config tab.

2. Expand Drop and choose Fixed Burst in Distribution.

3. Choose Repeat in Scheduling and enter 0.1 in Repeat Period.

4. Enter 20 in Burst Size.

5. Click Apply to apply the changes.

6. Click Start to start the impairment.

Fig. 27 Configure flow impairment

Now you can see the drop function is active. To stop the drop function, simply click Stop.

Fig. 28 Configure flow impairment

Chimera Statistics

Now let’s go to check the drop statistics.

1. Go to Global Statistics tab.

2. Click Chimera Statistics tab.

3. Under Total Counters, the RX and TX statistics on Flow (1) VLAN 10 show you the traffic statistics captured by the flow filter.

4. Under Packet Drop, you can see the drop statistics on Flow (1) VLAN 10.

Fig. 29 View impairment statistics in Global Statistics