Known Issues

  1. It is recommended to upgrade existing routers to the most current firmware including new out of the box routers before proceeding.  Old firmware versions below 3.0.0.4.376.1123 on these routers are very buggy, causing frequent phone and fax adapter registration failures and intermittent call quality problems.
  2. There has been reports of exploits that have been addressed and corrected by Asus as of the latest firmware 3.0.0.4.378.4376 released 02/15/2015.  Please consult Asus for direct support on upgrading your routers. Link to Asus
  3. SIP ALG enabled by default, causing intermittent phone issues. 

Technical notes

  • R vs U models:  There is no difference in hardware or firmware between a R or U model.  The R indicates large retail stores such as Best Buy while U indicates online retail such as Amazon.
  • There are two versions of Asus supported firmware,
    • The official Asus-RT based firmware direct from Asus (Recommended) this config note only address the official Asus-RT
    • Asus Merlin-WRT which is a port from the Asus-RT .

Resolution

  1. Login to the router
  2. SIP ALG must be disabled. Click on Advanced Settings -> Administration -> System -> Enable Telnet -> Yes -> Apply
    1. If you don't have the option to Enable Telnet, try accessing the hidden page URL below:
      1. http://192.168.1.1/Main_AdmStatus_Content.as
        • Replace "192.168.1.1" with the IP address of the Asus router, if it's different. 
        • For example, if you Asus router is 192.168.2.1, then you would use the URL "192.168.1.1/Main_AdmStatus_Content.as".
      2. Once there, type:
        • telnetd
        • This will enable telnet for just the duration of your session.
    2. If the steps above still don't enable telnet, then you or your IT will need to call Asus to get help upgrading the router's firmware to the latest version since older versions do not have the Telnet option.  Smarsh Hosted Services cannot upgrade the firmware for you since it can cause unexpected router problems that only Asus or your IT can resolve.
  3. Connect to the router using PuttyTel or the operating system's telnet client.  Once connected, type:
    • nvram set nf_sip=0
    • nvram commit
    • reboot
  4. Depending on the firmware version, the commands above may not disable SIP ALG.  Verify SIP ALG is disabled by doing the following:
    • Log back into the router -> Advanced Settings -> WAN -> NAT Passthrough -> SIP Passthrough -> Disable -> Click Apply
  5. If the telnet commands above did not work and you didn't have the option in step 4:
    • Then you or your IT will need to call Asus to get help upgrading the router's firmware to the latest version since older versions do not have the ability to disable SIP ALG. 
    • Smarsh Hosted Services cannot upgrade the firmware for you since it can cause unexpected router problems that only Asus or your IT can resolve.
  6. This optional step is needed for call quality monitoring and troubleshooting purposes:
    • Go to Advanced Settings -> Firewall
      • WAN pings (or Respond Ping Request from WAN) -> Enable -> Click Apply
      • Logged packets type -> Set to Both -> Click Apply
  7. This step is only needed if you have or plan to purchase Polycom phones. 
    • It will require you reboot all your computers and computers so make sure to do it at a time when you can afford to lose internet connection:
      • Advanced Settings -> WAN -> Internet Connection -> WAN DNS Setting -> Connect to DNS Server Automatically -> Select No -> Then do the following:
        • DNS Server1: 8.8.8.8
        • DNS Server2: 8.8.4.4
        • Click Apply to save
        • Advanced Settings -> LAN -> DHCP Server -> DNS Server -> Enter: 8.8.8.8 -> Click Apply.
      • Note:  Asus standard firmware by default will partially disable DNS Proxy/Relay/Cache.  The above settings must be set to allow the Primary DNS Server to be set as 8.8.8.8 on any Smarsh Hosted Services phone.  The secondary DNS server will always default to the router's default gateway.  This may be corrected in future software.  Only Asuswrt-Merlin firmware will allow the adjustment and full disable of DNS Proxy/Relay/Cache.  See KB Asus Routers running Asuswrt-Merlin.
  8. Asus QOS
    1. Setup and results are based on ASUS RT-AC68 running firmware 3.0.0.4.378.4376 released 02/15/2015 and a RT-AC66 on firmware 3.0.0.4.376.3861.
    2. Adaptive QoS is not supported as its default settings do not allow for refinement and only has UDP ports 5060 define, It will not be covered.  If Adaptive is used Smarsh Hosted Services will advise to turn this option off and use Traditional.
    3. The Asus router handles VoIP traffic with no issues out of the box, however there may be a need to apply QoS as a precautionary measure to ensure the best possible optimization of your internal network.  These configurations are examples only and optional.  Consult your IT person if QoS is to be implemented on your network.
      • Under General > Adaptive Qos > QoS tab
      • Enable Smart QoS = Yes
      • Upload Bandwidth = XX “Where XX is your actual upload bandwidth”
      • Download Bandwidth = XXX “Where XXX is you actual download bandwidth”
      • QoS Type = Adaptive
      • Apply (The router will reboot)
    4. After the reboot and the router is back on line Under General > Adaptive QoS > Qos TAB choose
    5. Right Side Drop down choose user-defined QoS rules you will see...
      • Service Name – Source IP or MAC – Destination Port – Protocal – Transferred – Priority – Add/Delete
      • The example screen shot is for reference only.  Circled in RED are the add on devices established to give priority to the VoIP environment (Smarsh Hosted Services IP-Phones) You will need to consult with your IT person for further details on your internal network needs.

  9. You will see the following:

    Service Name – Source IP or MAC – Destination Port – Protocal – Transferred – Priority – Add/Delete.  The example screen shot is for reference only.  Circled in RED are the add on devices established to give priority to the VoIP environment (Smarsh Hosted Services IP-Phones) You will need to consult with your IT person for further details on your internal network needs.

  10. You or your IT will need to manually upgrade the router's firmware to the latest version from Asus' website

    NOTE: It is always recommended to keep up to date on the Routers firmware.  Asus makes this extremely easy to do manually.

    • Go to Administration > Firmware Upgrade
      1.  Firmware Version -- It is not recommended to use this option.  Though this vulnerability has been corrected (LINK) in version 3.0.0.4.376.1123 it is recommended to always download any firmware from the Official ASUS support website.
      2.  Restore/Save/Upload > Save setting = save (Save the CFG File to a location on your computer)
    • This resolves severe security vulnerabilities Asus has known about since the start of 2014 but still did not resolve as of June 2014.
    • Firmware 3.0.0.4.374.5047 and later is required to prevent your network and phones from being compromised.
    • We have run into many cases where these routers block the phones' NAT Binding/Keep-Alive messages that are sent every 15 seconds.
    • This causes the phones/fax-adapters to fail to register, which causes call and many other phone/fax feature failures.
    • They are either resolved by a firmware update or by replacing the router with a different serviceable router or a recommended one.
    • Smarsh Hosted Services cannot upgrade the firmware for you.  If you need help, contact Asus.
    • Smarsh Hosted Services also cannot replace the router for you if a firmware update does not resolve the issue.