Skylight performance element: LT 7.9.1 Release Notes

These release notes cover the requirements, new features, changes, addressed issues and known limitations for the Skylight Element: LT firmware version 7.9.1. Please read all the notes prior to installing this firmware version. For more information, refer to the Skylight Element: LT User Manual.

Organization

This manual includes the following sections:
Requirements
This section provides requirements for Firmware Version 7.9.1.
Firmware Version 7.9.1_23673 (2020-11-12)
This section provides New Features and Enhancements, Addressed Issues, Operational Considerations/Known Limitations and MIB Changes, if any, for Firmware Version 7.9.1.

Product Name Changes

The following Accedian products were renamed in March 2015. References to these products in this document reflect the new naming conventions.

Requirements

This firmware version applies to the following Skylight element: LT. Resulting from changes in the TLS version, the following software versions are compatible with SkyLIGHT Director Vision 1.3 (Now Skylight orchestrator) and above:

• 7.1.1.1
• 7.3.0.3
• 7.4
• 7.5
• 7.6
• 7.7
• 7.8
• 7.8.1
• 7.8.2
• 7.8.2.1
• 7.8.3
• 7.9
• 7.9.1

Firmware Version 7.9.1_23673 (2020-11-12)

New Features and Enhancements

Disregard Pbit in DMM
Disregards Pbit in DMM available in the uSOAM stack by inserting of the Test-Id-TLV in each DMM packet sent. This TLV is to be used to differentiate DMR flows (in RX) instead of the currently used p-bit.

Skylight performance element GUI Enhancements
The GUI has been enhanced to make it easier to read, these changes include:

• Deep navy color for the text.
• Changed the font to medium instead of normal or bold.
• Borders are thicker and deep navy colour.
• More space was added between blocks to ensure the GUI is less compact.
• Menu has more space and menu items selected are bolder with shading in the selected menu tabs.

Operational Considerations

Important Notes

• The Skylight element: LX firmware is delivered in a consolidated file prefixed by “ACC”, e.g. ACC_7.X_YYYY.afl. This file contains the firmware for the GT, GX , LX and LT Performance Element products. It cannot be used with any other product.

• IMPORTANT: Prior to upgrading the firmware on a unit where the History Buckets feature is enabled, certain precautions may need to be taken to prevent a loss of history data during the upgrade. Before proceeding with the firmware upgrade, take the following precautions:
• To prevent any loss of history data, ensure that all data has been transferred to the file server.
• Be aware of certain side-effects caused by these optimizations on systems on which the History Buckets feature is enabled.

• In a G.8032 ring configuration, the Skylight element: LX supports a maximum of 62 policies on the LAG port (i.e. policies that govern how traffic is dropped from the ring to UNI ports). This limitation does not apply to the UNI ports (i.e. policies that govern how traffic is added to the ring) unless the VLAN-tagged customer traffic is passed transparently from the UNI port to the ring through one-to-one mapping.
• One way to avoid this limitation and maximize the number of usable UNI policies is to encapsulate multiple customer VLANs (coming from the UNI) under a single service provider VLAN on the ring. Doing so reduces the number of policies required by the LAG port.

Copper LAG port state changes from Up > Dormant > Down instead of Up >Down while link is disconnected
When a connected link goes down, the port is expected to switch from Up to Down quickly, however, the port is switching from Up to Dormant and then to Down.

Cannot create the second VCA when 2 Operator’s TPID are different
When Operator1’s TPID and Operator2’s TPID are different, only 1 VCA will be successfully created. In this scenario, a second VCA cannot be created. This is a limitation of the VCE/VCA model and it will result in the following error message: “This platform doesn’t support this feature”.

Flow-1 automatically switches back to out-of-service mode during upgrade process
When upgrading the performance element from a pre-7.7 release, if both RFC2544 flows were enabled, then the “Flow type” field in the “First flow profile settings” will be automatically reconfigured to the “Out-of-service” state as part of the upgrade process.

LBR message still occurs when MIP and MEP are different VLAN type
Unicast CFM-LBM frames sent to Accedian Demarcation devices are VLAN TPID unaware.
ATRC-D17907 Missing packets on RFC2544 generator layer-3 (2 flows)
With an RFC2544 generator layer-3 that has flow 1 set as QinQ and flow 2 set as no encapsulation (or QinQ), packets are missing on flow 2 after completing the RFC2544 with two flows.

Error loading proper page indexing when loading pages via URL/back
Possible error loading proper page indexing when loading WEB pages that contain paged tables via URL (i.e. back). Some WEB pages contain a table paging feature that displays a certain number of instances per page within a table. As the user cycles through the different pages, he will be able to view different instances and the URL will be updated to save this information. This allows a user to re-load the same view by using the URL (i.e. saving bookmark, clicking back to reload page, etc.). However, when reloading a web page using this method, incorrect index offsets may be observed for instances on certain pages.

Generator RFC2544 in-service and monitor operate incorrectly
When an L2PT rule is enabled with forwarding mode set to either pop or replace and the frame is S-VLAN tagged, the frame is dropped instead of being forwarded.
ATRC-D16848 Filter does not catch IPv6 Extension Headers
Because the frame header fields extraction depth is limited to the first 96 bytes of a frame, any fields of an IPv6 frame that are beyond the first 96 bytes will not be extracted. Therefore, they will not be found in the classification key used against an IPv6 filter.
Also, the following IPv6 Next Headers identifying Extension Headers will be skipped. Therefore, they will not be found in the classification key used against an IPv6 filter:

• Hop-by-Hop options (0)
• Destination options (60)
• Routing header (43)
• Fragment header (44)
• Authentication header (51)
• Mobility header (135)

SNMP IPv6 Filtering and Loopback is not supported
SNMP IPv6 Filtering and Loopback is not supported in this release.

LBR message still occurring when MIP is created with MD level
Unicast CFM-LBM frames sent to Accedian Demarcation devices do not validate the MEG level in the frame.

DOWN MEP using VCE does not work with un-tag packet
We do not support EVC Client Interface for an untagged MEP on a VCE. We only support untagged MEPs, if it is a Down MEP on a physical port of the VCE.

The TP-Z-PCP-Mapping does not work properly
An Up MEP defined on the TP-Z port of a VCE, which is defined with frame-type ‘all-to-one’, does not support the PCP mapping since it necessarily becomes untagged when egressing TP-A. The PCP value used is then inherited from the CFM object when additional components are in the transmission path.

DownMEP_VCE: VCE is using TPID but it is affected by changing s-vlan mode 0x9100
The user needs to configure the S-VLAN ethertype located under General system settings, prior to configuring any VCE or CFM elements. If the user changes this setting after configuring other elements, they may see some display discrepancies.

LAG Port remains DOWN with LACP, but UP with Link status
When using LACP, if the catchall L2PT rules are enabled, LACP frames will not be handled correctly to allow LACP to operate correctly.
Workaround: Create LACP rules that also apply to the L2PT configuration.

Limited availability of the OAM Loopback feature
The 802.3ah OAM loopback feature is not functional on the following platforms:

• Skylight element: GT
• Skylight element: GX
• Skylight element: LT
• Skylight element: LX

Reserved value no longer allowed in a Y.1731 configuration
As of firmware version 6.4.2, VLAN ID 4095 is a reserved value and is no longer allowed in Y.1731 configurations.
If VLAN 4095 was used in a previous firmware version, support in version 6.4.2 will be maintained through a firmware upgrade. However, any MA/MEG instances using VLAN 4095 cannot be recreated in the event of a deletion.

SNMP returns incorrect values for certain PAA configuration parameters
Polling the following PAA configuration OIDs with SNMP returns “0” instead of the actual value:

• acdPaaUdpCfgOneWayDelayMax
• acdPaaUdpCfgOneWayDelayThresh
• acdPaaUdpCfgOneWayAvgDelayThresh
• acdPaaUdpCfgOperationMode
• acdPaaUdpCfgPktSize
• acdPaaUdpCfgSamplingPeriod
• acdPaaUdpCfgPeerID

L2PT rules for ESMC also catch other slow protocols
An L2PT rule configured for the ESMC protocol may also catch the following protocol frames:

• Link OAM
• LAMP
• LACP

If separate L2PT rules are not required for these protocols, no specific intervention is necessary.
If separate L2PT rules are required for these protocols, assign a higher rule ID to ESMC to ensure that it does not interfere with other protocols. As a result, other protocol filter rules will be processed before the ESMC rule.

VC Agent: Changing the local time can cause a disconnection from Vision EMS
Changing the local time on a unit can cause the Vision Collect agent to disconnect from Vision EMS. The agent will reconnect automatically. No PM data is lost; if a transfer is interrupted, the data will be retransferred once the connection is restored.

Slight variation in BLUE queue full/empty threshold percentage values
The Web interface for the following products accepts values between 0 and 100 for the BLUE Queue Full Threshold and BLUE Queue Empty Threshold parameters:

• Skylight element: GT
• Skylight element: GX
• Skylight element: LT
• Skylight element: LX

These values are expressed as percentages. However, this percentage value is subsequently converted to a binary number and mapped to the range 0-128, as the underlying register is 7 bits in length.
In most cases, the initial percentage will not correspond to an exact binary value. When this value is then converted back to a decimal percentage for display purposes, the end result may differ slightly from what was initially entered.

History CSV files may not all contain the same range of period numbers
The exported history CSV files may not all contain the identical range of period numbers, depending on when the given history metrics were collected. Enabling multiple categories of history metrics with many instances requires more processing than history metrics with fewer categories and instances. Since the history files are processed sequentially, some exported files may consequently present different period numbers compared to others.
For example, the CFM DMM file may show periods 16-30, whereas the CFM SLM file may show periods 17-31, since it was processed afterwards. The reason for this variation is that new periods are included in the CSV file as soon as they become available.
This is the expected behavior. There is no period number synchronization between history categories. Note that all periods are exported in the CSV files and no data is lost.

CoS Mapping: Yellow PCP Out is not mapped to a queue
The following products use CoS mapping to define the internal CoS that service frames will use in the unit.

• Skylight element: GT
• Skylight element: GX
• Skylight element: LT
• Skylight element: LX

However, the pre-marking color parameter (set to Green or Yellow) is disregarded when mapping a flow to a traffic queue. The system’s internal CoS always uses the configured Green PCP value to map a flow to a queue, regardless of whether the pre-marking is set to Green or Yellow.

Web Interface: VLAN ID value not properly validated when creating a VID set
The VLAN ID value is not properly validated when creating a VID set in the Web Interface. Entries outside the valid range (0–4095) are accepted, as well as character strings; however, the resulting VID set instance is empty with no VLAN ID assigned.
This issue only concerns the Web Interface; the CLI performs the proper validation and rejects invalid entries as expected.

The following products and firmware versions are affected:

Syslog error message at login after configuring RADIUS
After a first-time RADIUS configuration, a false syslog error may be generated due to start-up conditions when the user logs in.

The syslog message is as follows:
Jan 1 00:19:13 C074-0010 dropbear[1620]: rc_get_seqnbr: fscanf failure: /tmp/radius.seq

This message has no consequence and can be ignored.

Modified syntax for CLI command “bandwidth-generator add”
Starting in firmware version 6.4, the CLI command bandwidth-generator add is used to configure regulators and bandwidth sharing envelopes.

Previous syntax (before 6.4):
bandwidth-regulator add …

New syntax (6.4 and later):
bandwidth-regulator add regulator …
or
bandwidth-regulator add envelope …

Consequently, the word regulator is reserved as of firmware version 6.4 and cannot be used as a regulator name, although the former syntax is still supported for backward compatibility.

These changes are illustrated in the following examples.

Preferred syntax:
bandwidth-regulator add regulator regulator1 cir 20000 …

Allowed (for backward compatibility):
bandwidth-regulator add regulator1 cir 20000 …

Not allowed (triggers an error message):
bandwidth-regulator add regulator cir 20000 …
(invalid parameter value)

Maximum number of complex rules for ERP traffic
For any unit that supports G.8032, the system automatically creates a default Layer-2 filter traffic policy (used for the ring pass-through traffic) whenever a LAG port is configured for ERP.
Since this default policy consumes one of the unit’s available complex rules (i.e., using a Layer-2 or IPv4 filters), the number of complex rules available to users on that LAG port is reduced by 1. This situation has no impact on other ports.

Timestamps of report periods are not always contiguous
The data collected by Vision EMS in high-resolution mode can occasionally show consecutive records with timestamps that are not contiguous.

Be aware of the following limitations:

• When data is collected in high-resolution (1 second) mode, two consecutive measurements can sometimes present the same timestamp, or show a gap between the timestamps. This is caused by rounding the time value to a granularity of 1 second.
  Please note that in this case, no periods or measurements are lost, i.e. all periods are consecutive, and none are missing.
• There can be a timestamp gap or overlap when the unit is first synchronized by NTP, PTP or GPS. As the Flow meter may be acquiring data before the synchronization is complete, a time adjustment could affect the timestamps. No periods or measurements are lost.

Inconsistencies may also surface in the timestamps collected before a system reboot when compared to those collected after the reboot.

New behavior when re-enabling CFM-PL instances
In firmware version 6.3.1, the CFM packet loss (PL) behavior has been modified as follows:
Previous behavior (before 6.3.1): When a packet loss (PL) instance is re-enabled after being disabled, the current period results contain the last values from the point at which the instance was disabled.
New behavior (6.3.1. and later): When a packet loss (PL) instance is re-enabled after being disabled, the current period results are cleared, and measurements begin from 0.

Syslog: Entries are sometimes not displayed in the system log
When a large number of events occur at the same time (e.g. raising or clearing hundreds of alarms simultaneously), some entries may be absent from the syslog. Missing entries do not imply that the corresponding events/actions were not properly executed.
For example, in the case of alarm storms, although syslog messages for some status changes are not displayed, all the alarms are updated to the correct status and the corresponding SNMP traps are reported.

RFC-2544 testsuite: Report displays incorrect unit identifier information
When running the RFC-2544 testsuite after modifying the unit identifier (System ▶ DNS ▶ host name), the generated report contains the previous unit identifier.

Firmware upgrade considerations pertaining to history buckets
Since firmware version 6.3.1, several software modifications have optimized how the history data is handled and stored to flash memory. Before proceeding with the firmware upgrade, take the following precautions:
To prevent any loss of history data, ensure that all data has been transferred to the file server.
Be aware of certain side-effects caused by these optimizations on systems on which the History Buckets feature is enabled.

Y.1564 one-way flows must be received on the same SAT server port
If one-way test flows from multiple Y.1564 generators are sent to a SAT server (i.e. a remote unit), all flows must terminate on the same physical port. For example, terminating eight flows on one port and eight other flows on a different port is not supported.

No VLAN information in LLDP frames
LLDP frames sent by the unit only contain the interfaces’ IP address and index values. Information on the interfaces’ VLAN settings is not available at this time.

RFC-2544 monitors are not independent
When using both RFC-2544 monitors in bypass mode to monitor Layer-2 and Layer-3 test traffic flows, both monitors will report the Layer-3 flow statistics. If the monitor configured for Layer-2 is disabled, the other monitor (Layer-3) does not report any statistics.

Obtaining the UTC offset from the PTP master is not supported
The option to obtain the UTC offset from the PTP master is not yet supported. As such, the offset provided in the announce messages from the PTP master are not applied to the time information on the unit. Only the locally defined UTC offset can be used.

IPv6 router-advertised addresses are lost when configuring other addresses
After an interface has configured itself with one or several addresses from IPv6 router advertisements, configuring any other address (whether static or DHCP) will flush the router-advertised addresses.
This is the intended implementation, since configuring a static IP or enabling DHCP supersedes the router advertisements.

Higher number of Y.1731 frames sent over a period
The number of Y.1731 sample frames (CCM, DMM or SLM) sent over a period can be slightly higher than expected.
For example, if SLM is configured with an interval of 100 ms and a period of 60 seconds, it is possible that 601 or 602 samples will be sent during the period instead of 600. This is caused by a rounding issue related to timer division.
This issue does not lead to packet loss or inaccurate delay results; it is merely a variation of the number of samples sent over a period.

Plug & Go ring protection from customer beacon
When a new unit is added to a G.8032 ERP ring and is in the process of being provisioned using the Plug & Go feature, it is important to ensure that no foreign beacons enter the ring from the UNI side (e.g. from a customer). Taking this measure prevents the new ring unit from being provisioned by the wrong beacon.

Web interface may be slow with Mozilla Firefox version 14.0.1 to 22
When using the Mozilla Firefox Web browser version 14.0.1 to 22 to manage the unit, the response time can sometimes increase, which makes the Web interface slow to operate.
Workaround: Use Firefox version 23 or higher.

LAG-Protection: ETH-CSF cannot validate port state on LACP-based UNI links
If enabled, ETH-CSF cannot validate the link status of an LACP-based protected UNI link. Under such circumstances, the remote fault cannot be propagated. Since ETH-CSF is based on link-status and LACP is based on signaling, it is currently impossible to indicate to CSF that the link is logically down, yet still physically up.

CLI traceroute command does not support all listed options
The CLI traceroute command does not support the following options:

• -q (number of queries)
• -s (source IP address)
• -g (gateway)

VSP reflector responds to invalid MAC addresses on the management port
The V-NID reflector functionality is only intended for use on traffic ports, not on out-of-band management ports. However, the out-of-band management port will reflect any ETH-VSP frames it receives. While traffic ports only reflect VSP frames that match the port’s specific MAC address, the out-of-band management port will reflect VSP frames that match the MAC address belonging to any of the unit’s ports (MAC range).

EVC Mapping: “Preserve VLAN - New CFI/PCP” limitations
When setting EVC Mapping to “Preserve VLAN - New CFI/PCP”, the following limitations should be taken into consideration:

• DSCP/IP Precedence information is not extracted from triple-tagged frames.
• DSCP/ IP Precedence information is not extracted from 802.2 SNAP/LLC frames.
• DSCP/ IP Precedence/PCP information is not extracted from S-VLAN (0x9100) tagged frames, unless 0x9100 is set globally as the default S-VLAN Ethertype.

This EVC mapping action can corrupt untagged frames. Therefore, a filter matching at least one VLAN must be used to ensure the classified frames are tagged.

EVC mapping actions that modify VLAN tags must not be used with untagged traffic
EVC mapping actions that involve replacing or modifying a VLAN tag should not be used if the traffic is untagged. These EVC mapping actions are:

• Replace
• Pop & Replace
• Preserve VLAN – New CFI/PCP

Performing VLAN modifications on untagged traffic could result in altering the frames. There is no traffic policy validation to enforce the presence of a VLAN filter with these EVC mapping actions. You must therefore ensure that any policy using these EVC mapping actions is configured with a VLAN filter.

Frame count statistics may be inconsistent if SLM is disabled in mid-period
If an SLM instance is disabled in the middle of a reference period, the ETH-SLM and ETH-SLR frame counts shown in the MEP statistics may not be consistent with those shown in the SLM statistics. This is normal, as the information may not have been refreshed at the very moment when the SLM instance was disabled.
This behavior is a normal consequence of disabling the SLM instance during a period and is by design. SLM functions as expected in continuous operation.

CPU-destined ingress traffic can be processed on an LACP link while not in the collecting/distributing state
When using LACP status-based protection, CPU-destined traffic received on a port can be processed by the software even when the local (actor) LACP link status is not in the collecting/distributing state. This situation applies to CFM traffic (LBM, LTM, DMM, CCM, etc.), PAA traffic and L2PT traffic.

Web session does not time out if automatic refresh is enabled
The active session of the Web interface will never time out if automatic refresh is enabled in a page.

ARP Requests are sent out on a port when interface is disabled
Many ARP requests are sent out on a port even if the interface associated with the port is disabled.

“cfm show statistics” CLI command shows incorrect RDI and CCM sequence errors
This CLI command does not accurately report the count of CCM sequence errors. This information can be displayed using the cfm show mep statistics command.

Users without “Policy” permissions can clear policy statistics in the Web interface
Users are currently able to clear the Policy statistics in the Web interface (but not in the CLI), regardless of their assigned permission settings.

CLI: CFM naming convention (MEP, Pkt-loss, DMM)
When assigning a CFM name to an instance in the GUI, the name must not be composed solely of digits; CFM names must always include at least one letter. If the name contains only digits, the CLI interprets the name as an instance index.

SCP -z option not working with certain servers
Certain SSH servers, such as Solaris and several Linux enterprise versions, do not support the SCP -z option to specify the username. Once the SCP fails, FTP no longer functions since it uses the same process. The CPU must be restarted for FTP to function.
This issue is related to how the SSHd server is configured. Servers are usually configured to use PAM (Pluggable Authentication Modules) for account and session management. SSHd can also rely on PAM for authentication; PAM then executes its authentication scheme based on its configuration for that login method (for example: /etc/pam.d/sshd).