Known Issues

  1. SIP ALG is poorly implemented, causing many call and feature failures. Some firmware versions have a bug that does not allow disabling SIP ALG.
  2. Load-balancing 2 WAN interfaces will cause intermittent call failures.  Assigning the phones to use only 1 WAN or using WAN failover instead is required.
  3. We need more information on this router to find out if the other basic router requirements can be made on this router.
    • Please contact Smarsh Hosted Services Voice Technical Support so we can better document other necessary changes that need to be made to this router.

Resolution

  1. Go to Advanced > NAT > ALG:
    • SIP ALG: Disable.
    • Click Save.
    • Note: If SIP ALG goes back to 'enabled' after pressing Save then the current firmware version on the firewall has a known bug. To resolve, you will need to contact TP-Link support and get the beta firmware release that fixes this issue: TL-ER6020v1_en_1.1.0_[20150616-rel72317].
  2. This optional step is needed for call quality monitoring and troubleshooting purposes:
    • Go to Firewall > Attack Defense > Attack Defense:
      • Block Ping From WAN: Uncheck.
      • Click Save.
  3. We need more information on this router to find out if the other basic router requirements can be made on this router.Please contact
    • Smarsh Hosted Services Voice Technical Support so we can better document other necessary changes that need to be made to this router.