PMP450x Release 21.0 is now available

Cambium is officially releasing the PMP450x Radio 21.0 software.

Radio software and documentation can be found at Log In / Cambium Networks Support, and available on cnMaestro cloud.

Upgrade Subscriber Modules (SMs) first to System Release 20.0 or later version and then upgrade the AP. Otherwise, SMs will connect but at a maximum modulation rate of 2X MIMO-B, until both sides are running on System Release 20.0 or later version.

New Features

The following features have been introduced in System Release 21.0

PMP Nomadic Mode

This feature allows for position movement and automatic re-ranging of SMs within a sector. The PMP Nomadic mode requires a Feature Key to enable at the AP. SMs do not require a Feature Key to enable. Operators are suggested to contact Cambium Networks through their RTM or customer support for additional details on configuration and operation.

Note: This feature is not supported on PMP 450m and in PTP modes.

The Nomadic Mode page is applicable for all modules (AP/SM) as shown in this screenshot.

Note: New statistics for Nomadic Mode are also available. Refer the PMP 450 Configuration Guide for more details.

Allowing more than 255 slots in any direction

The System Release 21.0 enables a 5 ms frame period for 40 MHz channel bandwidth on 450m. It also enables all 450 platforms to have the maximum downlink data percentage of 15-85% at 5 ms frame. Before release 21.0, other APs and BHM had a maximum limit of 253 data slots in a single direction, which previously limited the downlink data percentage range from 34% to 67% at 40 MHz and 5 ms frame. Note that although System Release 21.0 is introducing support for 5 ms at 40 MHz on 450m, further improvements are scheduled for upcoming releases. So while this initial introduction for 450m provided some sector benefits, some deployments may still see better performance with 2.5 ms frame at 40 and 30 MHz channel bandwidths.

Note: The maximum throughput to a single Data Channel remains at 175 Mbps even in System Release 21.0. At some high signal levels, the throughput to a single Data Channel will be lower. To fully test this configuration, use Link Test with Multiple LUIDs or multiple Data Channels to see the increase in sector performance. This will be improved in a future release.

Note: SMs need to be on System Release 16.1 or later version to register to an AP with configuration of greater than 253 data slots.

Default Port VLAN ID for AP

This feature allows the user to configure the default port VLAN ID on the AP. When VLANs are enabled on the AP, any untagged frames at AP’s Ethernet ingress are tagged with default port VID. The Default Port VID can be configured in Configuration → VLAN tab, as shown in this screenshot:

This screenshot shows the active VLAN configuration:

MAC Address Filtering

This feature allows the user to filter frames that ingress the Ethernet interface of the radio. The frames are filtered based on the source Ethernet MAC address of an Ethernet frame.

This feature is supported on all platforms. To configure this feature, follow the below steps:

  1. Navigate to Configuration → Filters tab.
  2. Set Filter Control to MAC Address Filtering Enabled.
  3. Choose the Filter Default Action.
  4. Enter the source MAC Address to be filtered and choose the action.
  5. Click Add/Modify button.


Any changes made to MAC Address Filtering configuration, when saved, do not require a reboot and the changes are effective immediately. Users should be careful when enabling this feature, with Filter Default Action set to Deny all, particularly on AP/BHM/BHS. In such a case, Ethernet access to the radio is allowed only from the device whose MAC address is in the MAC Address Filters table with action set to Allow.

The source MAC address can be a unique MAC address or a manufacturer’s OUI. The MAC Address and OUIs can be added in any of the following formats:

  • OUI: aa:bb:cc or aa-bb-cc or aabbcc
  • Single MAC: aa:bb:cc:dd:ee:ff or aa-bb-cc-dd-ee-ff or aabbccddeeff

This screenshot shows an example of MAC Address filter configuration with default Action set to Allow all:

If the Filter Default Action is set to Allow all, any frame whose source MAC Address or OUI is:

  • in the MAC Address Filters table and action is set to Deny, will be blocked from passing through.
  • in the MAC Address Filters table and action is set to Allow, will be allowed to pass through.
  • not in the MAC Address Filters table will be allowed to pass through.

This screenshot shows an example of MAC Address Filter configuration, with default Action set to Deny all:

MAC Address filter configuration with Deny all

If the Filter Default Action is set to Deny all, any frame whose source MAC Address or OUI is:

  • in the MAC Address Filters table and action is set to Deny, will be blocked from passing through.
  • in the MAC Address Filters table and action is set to Allow, will be allowed to pass through.
  • not in the MAC Address Filters table will be blocked from passing through.

The MAC Address Filter statistics are in the Statistics → Filters tab, as shown in this screenshot:

MAC Address Filter statistics

EIRP Change History in CBRS band

The Statistics → CBRS page displays CBRS heartbeat statistics and CBRS EIRP Change History. This page is visible only on the AP/BHM. The statistics for the SMs can also be seen on this page, viewed on the AP/BHM radio, by selecting the SM of interest via the Select CBSD drop-down menu. The EIRP Change history is available in the Statistics → CBRS tab, as shown in this screenshot:

EIRP Change History

Channel Change History

The Channel Change History statistics are available for all PMP AP and BHM products. For non-CBRS deployments, the authorized grants column is not visible, and only the user-triggered channel change history is displayed. The Channel Change History is available in the Statistics → Channel History tab, as shown in this screenshot:

Channel Change history

GPS data reporting functionality on SM and BHS

This feature adds the ability to display real-time GPS data on an SM or BHS, including on a MicroPoP AP configured as an SM. The data is retrieved from a UGPS or cnPulse module connected to the device’s Aux Port using the appropriate cable or, in the case of a MicroPoP SM, from the onboard GPS receiver. The UGPS or cnPulse may optionally be powered by the Aux port on a 450i or 450b SM or BHS. When the feature is enabled, the GPS information is displayed on the Home → GPS Status tab, as shown in this screenshot:

GPS Status

Note: For MicroPoP hardware, while it is scanning as an SM looking for an AP to register to, there will be around a 10-second duration during scanning where the GPS information is stale while the unit is reconfiguring.

User accounts with default passwords

This feature alerts the user if there are any user accounts with blank passwords. If all the user accounts on the radio are using blank passwords, for example, when the radio is reset to factory defaults, the following message is displayed, as shown in this screenshot:

Security Warning: Configure login credentials to prevent unauthorized access

If at least one of the user accounts has a non-blank password, the user can not login into the accounts with a blank password.

Users can only login to the accounts with non-blank passwords. Once logged in, if the user access level is INSTALLER or TECHNICIAN or if user access mode is Read-Only, the following message is displayed as shown in this screenshot:

Security Warning: There are accounts with a default password

If the user access level is ADMINISTRATOR and user access mode is Read-Write, the following message, indicating the account(s) with a blank password, is displayed as shown here:

Security Warning: The following accounts have a default password: admin root

Report SM Reconnection failure after Channel/EIRP Change

When the AP has determined to change the frequency, the Bandwidth or the EIRP/Tx Power, it first takes note of the number of SMs that are currently attached to it, and any SMs that had been attached anytime in the last 12 hours.

After the switch to the new parameter, the AP compares the number of SMs re-attaching to it to the original number. After 10 minutes, if the two numbers do not match, the AP raises an alarm indicating that not all SMs have re-attached, along with a warning banner on the AP. cnMaestro 3.1.0 or later version will be required to view and clear the new alarm.

This functionality was designed primarily for CBRS operators, where such changes might be initiated by the SAS. It is supported on non-CBRS sectors as well.

The feature can be configured on the Configuration → General page of the AP as shown here:

SM Reconnection

Note: New counters for this Reconnection Failure feature are available on the Home-> Session Status page of the AP. Refer to the PMP 450 Configuration Guide for more details. Note that this table of counters is not normally visible and it is not visible after an AP upgrade or reboot. The table will appear and begin updating when a channel/EIRP change has been made.

Additional Enhancements

Products Affected Tracking Description
All CPY-17807 If a password is set on one account, reject no password accounts.
All CPY-17795 Added Egypt country code.
CBRS CPY-17789 Limit channel bandwidth in the channel hunting algorithm when some channels are not available from the SAS.
CBRS CPY-17788 Added weights to channel hunting algorithm for additional optimization of channel selection.
CBRS CPY-17719 Recognize when Federated Wireless is not sorting channels in the spectrum inquiry response.
CBRS CPY-17706 CBRS alarm and event improvements and additions.
All CPY-17575 Added CSRF Web protection option.

Problems and Limitations Corrected

Products Affected Tracking Description
AP CPY-17814 Do not log Dropping Control Packet on Broadcast VC.
450m CPY-17747 SM sometimes sends ACK at unsupported modulation when connected to 450m.
CBRS AP CPY-17702 AP does not request correct EIRP after CBRS SAS recommends a lower value than requested.
AP CPY-17698 AP sometimes does not fetch the time from the NTP server.
SM in NAT CPY-17693 SM in NAT mode is ARP broadcast storming the network gateway.
SM in NAT CPY-17593 SNMP addPortFwdMap remove support.
450i AP CPY-17800 DAGT crashed shortly after bootup on 450i AP while running System Release 21.0.
CBRS CPY-17806 450m not transmitting after suspension if the DPA suspension is only one heartbeat in duration.
CBRS CPY-17821 Round the EIRP to one decimal precision in an EIRP history table.
CBRS CPY-17701 Removal of SAS suggested EIRP from CBSD logs for operators using Federated Wireless SAS to prevent overfilling logs.
CBRS CPY-17733 In a few rare CBRS DPA suspension scenarios, the original channels/grants are unexpectedly relinquished and the temporary channels made permanent.
450m CPY-17711 450m link test does not send data over UHP traffic VCs.
SM CPY-17296 IPv6 multicast getting looped back to SM it originated from (also included in System Release
US 5 GHz CPY-17345 Radios that have run or STA-1 automatically allow FCC STA frequencies.
MicroPoP CPY-17383 MicroPoP GPS shows a high Invalid Message Count.
CBRS CPY-17632 EIRP and channel change history are available after reboot.
All CPY-17638 LQI calculation use the proper time for EVM samples
SM CPY-17649 Long Registration Times for SMs running System Release 20.3 and 20.3.1. This was also included in
AP CPY-17694 Occasional Fatal Error upon Bandwidth or Frequency change. This was also included in
CBRS CPY-17717 The interval between CBRS heartbeat requests is too low if no SMs registered.
450m CPY-17705 EIRP setting is not persistent through reboot if lowered from granted power.
CBRS CPY-17664 TX Expiry Time showing 12/31/1969 (CST) for a suspended grant.
All CPY-17380 Fixed crash in SSHs task.
AP CPY-17441 AP not falling back to valid DNS NTP servers if invalid IP entry configured.
SM CPY-17480 SM is not able to connect to on-prem cnMaestro due to SSL ERROR.
All CPY-17273 GUI becomes unresponsive after nping/nmap using IPv6 address.
450b BHM CPY-16908 Reboot is no longer required to change Aux Port Power to UGPS. Changes to the Aux Port configuration that affect UGPS power will also take effect immediately upon saving.

Known Problems or Limitations

Products Affected Tracking Description Workaround
450i SM/BHS CPY-17849 The Aux Port Power to UGPS parameter may become inaccessible after a 450i AP or BHM is converted to an SM or BHS. When this happens UGPS power cannot be enabled or disabled, and if the GPS feature is enabled then the GPS data will not be displayed. Ensure that the Sync Aux Port configuration parameter is set to Sync Input before converting a 450i AP or BHM to an SM or BHS.
Any PMP CBRS deployments CPY-17721 The System Release 21.0 adds both an alarm and a red banner on the AP. When a channel/EIRP change, a user-configured percentage of SMs have not reconnected within 10 minutes, if an operator makes another change while the alarm and warning banner are active, the banner is cleared when this second change is made, but the alarm is not. This inconsistency will be addressed in a future release. None. Required an alarm and warning banner inconsistency that can be seen.
All 3 GHz CBRS enabled AP/BHMs CPY-17791 One of the changes in System Release 21.0 was to remove the Configuration → CBRS → Multiple Grants enable/disable flag. While System Release 21.0 will still support existing wide grants that were generated on prior releases, any new CBRS grants generated in System Release 21.0 will be mult-grants. If an operator were running with multi-grant disabled on a prior release, they upgrade their AP to System Release 21.0 and request multi-grants, then downgrade back to a pre-21.0 release. The AP will be in a granted state (not authorized state) and the sector will be down. Enable the multi-grant option while on System Release 21.0 and reboot the radio. Alternatively, upgrade back to System Release 21.0.
Any PMP CBRS deployment CPY-17677 The SM Reconnect Percentage alarm feature will track SM reconnect percentages for Bandwidth, TX Power, and Center Frequency changes for all AP types except the 450m. For a 450m, the feature works for EIRP and Center Frequency changes, but not for Bandwidth changes due to the required reboot. An operator have to check themselves for any SMs that did not reconnect after a bandwidth change on a 450m, as has been the case in all prior releases.
All CPY-17251 When running greater than 253 data slots the SMs BER statistic is incorrectly giving BER errors. None. This is an incorrectly displayed Bit Error Rate statistic. It does not directly impact throughput.

This is an excellent release and I highly recommend it. I’ve been running beta 4 and beta 6 across almost my entire network with no issues, and generally higher overall performance. Two thumbs UP!


Thanks, Eric. And we’ve found a few things from you testing the beta, which we appreciate!

Time will tell how good the release is. :slight_smile:

1 Like

Thanks for the continued support Cambium! I just pushed v21.0 to a 450 and a 450i however I am unable to configure the downlink data beyond 75% as implied by the release notes. Could someone please advise? (other settings are 5ms, 30MHz, 14mi, auto-contention enabled…)

Dynamic Frequency Selection bands (such as United States 5.4 GHz) requires radar detection and has a max of 75% downlink so the uplink is at least 25% so can meet regulatory requirements. Are you operating in a DFS band?

Ahh gotcha, yes that is the catch. I was overeager and assumed “all 450 platforms” encompassed 5.4GHz for some reason. Wishful thinking! Thanks.

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4 posts were split to a new topic: PMP450 Receive Sensitivities in 21.0

3 posts were split to a new topic: PLL Lock Lost on PMP450i

This really requires a feature key? I must admit I am disappointed.

After updating to 21.0, We’re noticing SMs showing incorrect values for Maximum Receive Power on the Receive Signal Quality page in the GUI. Anyone else seeing this?

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yeah I see the same thing

1 Like

Oops, there’a a bug! Thanks for reporting. I’ll aim to get it fixed in 21.1.

This bug has been fixed in 21.1 BETA-1.

CPY-17881 - Maximum Receive Power incorrect on GUI