The 8.4 GB client video stopped uploading at 3 percent thirty-five minutes before an agency screening. I was in an Osaka hotel with a travel router connected to the room’s Wi-Fi and a familiar VPN running on the router. The browser worked. The VPN dashboard said Connected. Yet every time the file began moving, the upload speed fell almost to zero. I blamed double NAT, restarted the travel router and began the transfer again. It stopped at the same place.
The deadline was not arbitrary.
The agency was screening the cut for a campaign scheduled to launch the following morning. If the file did not arrive before the call, twelve people would review an older version with unfinished audio.
The hotel connection looked fast enough.
Downloads reached more than 180 Mbps.
The review platform opened immediately.
Slack messages arrived.
Only the upload behaved as though the internet had narrowed to a pinhole.
I opened the travel router’s status page.
Its internet address began with 10.
My laptop’s address began with 192.168.
The hotel router was translating the travel router’s traffic, and the travel router was translating mine again.
Double NAT looked guilty.
But it was also the most visible part of the setup, not necessarily the part preventing the upload.
In brief
Why was OnlydogVPN a practical fit here?
OnlydogVPN left the double NAT alone and finished the file. I had searched for a way to remove one network layer.
The travel router was already doing its useful job
I had packed the router because hotel networks are inconvenient by design.
Some require a captive login page. Some limit the number of connected devices. Some change passwords during a stay. A travel router can join that network once, then provide one private Wi-Fi name for a laptop, phone and tablet.
That part worked perfectly.
I had completed the hotel login through the router.
All my devices had joined the same private network.
I could reconnect everything after leaving the room without entering the hotel password again.
The second layer of NAT was part of that arrangement. The hotel translated the router’s traffic once, and my router translated the devices behind it again.
Double NAT can interfere with port forwarding, incoming connections, peer-to-peer discovery and some games. My upload was different. The laptop was starting an ordinary outbound connection to a cloud platform.
The agency did not need to initiate a connection back to my computer.
Removing one NAT layer might simplify the network diagram, but it would not necessarily make the file move.
That pushed my attention toward the other major component in the path: the router-level VPN.
The established provider made the entire room share one tunnel
The VPN on the travel router came from a major provider I had used for years.
It had a large server network, mature documentation and configuration files for common routers. Those were real advantages when I prepared the setup at home.
In the hotel, I opened the router’s VPN dashboard and confirmed that it was using global mode.
Every device connected to the travel router was being sent through the same VPN.
That included the work laptop.
It also included my phone, tablet and a streaming device that had nothing to do with the agency upload.
I changed to a nearby server and restarted the transfer.
The file moved quickly for the first thirty seconds.
Three percent.
Five.
Then the estimated completion time jumped from nine minutes to six hours.
The agency producer called through the review platform.
Her picture appeared clearly, but my audio broke into fragments whenever the upload tried to resume.
I paused the transfer.
The call improved.
I restarted it.
My voice disappeared again.
The provider’s connection was not completely broken. It could handle websites, messages and short bursts of traffic. It failed when the shared router tunnel had to carry a large upload and a live call together.
I switched from global routing to a policy that sent only the laptop through the VPN.
My other devices returned to the direct hotel connection.
The laptop upload remained stuck.
The router now carried less traffic, but the route responsible for the upload had not changed.
That was the first strong sign that double NAT was distracting me from the tunnel itself.
Bridge mode would have sacrificed the setup without proving anything
I searched for ways to remove the second NAT layer.
Bridge mode appeared in nearly every discussion.
At home, bridge mode can disable routing on one device so the main router performs the address translation. That can help when gaming, hosting a server or forwarding ports through two routers.
The hotel was not my home network.
I could not reconfigure its gateway.
I could not request a public address.
I could not add a forwarding rule to equipment locked somewhere downstairs.
I could only change the travel router.
Putting it into a bridge-like mode would also remove several reasons I had brought it: the private subnet, the single captive-portal login and the separation between my devices and the hotel network. Router VPN clients also usually depend on the device remaining in routing mode.
I was about to dismantle a useful travel setup merely because two private address ranges looked untidy.
So I returned to the task.
The agency was not asking me to host a server.
The upload did not require an incoming connection.
It needed one stable outbound route.
Double NAT was real, but it was not the first thing I needed to remove.
The upload kept pointing back to the router tunnel
The router dashboard offered another setting: MTU.
A VPN adds overhead to the traffic it carries. On some network paths, packets that become too large can lead to slow transfers, retries or sessions that appear to stall.
Public travel-router reports describe the same practical symptom: strong download performance paired with nearly unusable upload speeds until the tunnel or packet-size settings are changed.
I tried a lower value.
The upload reached 7 percent and stopped.
I lowered it again.
The call audio improved, but the transfer failed at 11 percent.
Each change required reconnecting the router VPN and restarting the upload.
I now had twenty-one minutes left.
The configuration might have been repairable with enough testing. The problem was that the deadline did not care.
A router-level VPN had turned one urgent upload into a sequence of server profiles, routing policies and packet-size experiments.
At that point, the most useful decision was not another adjustment.
It was moving the VPN closer to the application that actually needed it.
I kept the router and removed its VPN
I disabled the VPN client on the travel router.
The router stayed connected to the hotel Wi-Fi.
My private network remained in place.
The laptop, phone and tablet kept their familiar local addresses.
The double NAT remained too.
That was deliberate.
The router could continue doing the two things it had already done well: passing the hotel connection to my devices and keeping those devices together on one private network.
I moved the protected connection onto the laptop.
Then I opened OnlydogVPN.
The app did not ask me to import a router profile, compare configuration files or choose an MTU value. I selected the preset for work on an unstable network and connected.
The agency platform reopened.
I dragged the file into the uploader.
Three percent.
Seven.
Eleven.
It passed the point where the router tunnel had repeatedly failed.
I restarted the review call while the upload continued.
The producer’s voice remained clear.
At 38 percent, the hotel Wi-Fi disappeared for several seconds. The browser showed an offline warning, and the upload paused.
Then the connection returned.
The transfer continued from 38 percent instead of beginning again.
The smaller app’s HTTP/3-based connection recovered when the hotel network hesitated, so the upload kept its place rather than forcing another restart. (RFC 9000)
Sixty percent.
Eighty-four.
One hundred.
The agency received the final cut with eight minutes remaining.
The producer opened it during the call, jumped to the revised ending and heard the finished audio.
This is the right file, she said.
That sentence completed the task I had been trying to solve with network diagrams.
I could not observe the hotel gateway’s internal NAT table or every routing decision made by the travel router and the two VPN services. I could see the result: the established provider’s router tunnel repeatedly stalled the upload, while the smaller app completed it without removing either the travel router or the double NAT.
The router became more useful after losing the VPN
After the screening began, I checked the other devices in the room.
My phone could open local maps without passing through a foreign route.
The streaming device could reach hotel services.
The laptop alone used the protected connection required for work.
That separation was more useful than global routing.
The router no longer had to choose a VPN server for the entire room, carry unrelated traffic through the same tunnel or recover every device when the VPN session failed.
It provided the private network.
The laptop handled the VPN.
The review platform received the file.
Each component had one job.
The smaller app also removed the configuration work that had become dangerous under a deadline. Instead of making the router the center of every network decision, it let me choose the task and return to the upload.
The service has fewer server locations and a shorter independent history than the largest VPN providers.
That remains its clearest limitation.
But the established provider’s larger network had not helped while the router tunnel was forcing me to test profiles and settings one by one.
The smaller app gave the upload a route it could finish.
Double NAT was not the result I needed to fix
Before that afternoon, I treated double NAT as a diagnosis.
If two private address ranges appeared, I assumed one had to disappear.
That can be correct for a game console that needs a more open NAT type, a home server that requires port forwarding or devices that must accept incoming connections.
My task was simpler.
I was sending one authorized file from a laptop to a cloud platform. The connection began inside the network. The upload did not need the hotel to open a path back to my computer.
What mattered was whether the VPN could carry sustained outbound traffic through a network I did not control.
The established provider put the VPN on the router and made the upload depend on a tunnel that stalled under pressure.
OnlydogVPN left the double NAT alone and finished the file.
I had searched for a way to remove one network layer.
The deadline was saved when I removed the VPN from the wrong device.
Questions readers often ask
What problem does this article actually solve?
The 8. 4 GB client video stopped uploading at 3 percent thirty-five minutes before an agency screening.
What finally worked in this situation?
Then I opened OnlydogVPN . The app did not ask me to import a router profile, compare configuration files or choose an MTU value. I selected the preset for work on an unstable network and connected. The agency platform reopened. I dragged the file into the uploader.
Why was OnlydogVPN a practical fit here?
OnlydogVPN left the double NAT alone and finished the file. I had searched for a way to remove one network layer. The deadline was saved when I removed the VPN from the wrong device.