Azure File Storage uses SMB 3.0's encrypted transport to enable access via the Internet.

This often requires organizations to unblock port 445 for outbound TCP traffic.

For many small businesses and residential homes, ISP's may block 445.

We have put together this Wiki page for people to add their ISP's based on their experiences. Please update the Wiki page with relation to whether your ISP allows or disallows use of SMB3 and a link to the ISP's policy.

Table of Contents



Below the alphabetically sorted list

Company URL Region Condition
AT&T   TBD Through a cellphone wifi hotspot
Frontier See TBD Allowed, however their website appears to indicate it is blocked - potentially this is just for inbound traffic.
Mediacom -   TBD  
CenturyLink   TBD  
Time Warner Cable      
Paxio   Silicon Valley  
DST Brunei
TelBru   Brunei  
Entel - Internet Mobile   Peru  
Vivo Fibra   Brazil

Home and Business users 

Verizon - Home and Business      



Company URL Region Condition
AT&T U-Verse      
Charter Spectrum       
Charter Spectrum Business      
Comcast See    
Cox Communication -Residential See: Cox Internet Ports Blocked    

Verizon Wireless - Through a cellphone wifi hotspot.  



    Through a cellphone WiFi hotspot.
Optimum Online   port 445 is disallowed for both residential and business accounts


TDS Telecom See    
Telenet   BE  
OnsBrabantNet Glasvezel   NL  

Rogers Cable (Canada)

  Canada All Home and SMB Services (including Ignite)

Claro Peru- All Home Service

NET Virtua (Brazil)   Brazil  
Movistar Peru-   Peru All Home Service

Vivo Mobile

  BR 4G, LTE and 3G
Movistar Peru- All Home Service      
Vodafone   India 4G, LTE and 3G


See also