On Mon, Jun 22, 2015 at 10:39 PM, Nicholas Oas <nicholas.oas@gmail.com> wrote:
Would anyone mind sharing with me their first-hand experiences with residential satellite internet?
Right now I am evaluating HughesNet Gen4 and ViaSat Exede and I'm thinking specifically as a sysadmin who needs to use the uplink for work, not surf.
What are your experiences with the following applications? -SSH, (specifically interactive CLI shell access) -RDP -SIP over SSL -IPSec Tunneling (should be a non-starter due to latency) -GRE Tunneling
Working for an satellite ISP I can give you some technical background. We're only target enterprise/government/military customers with more specific use cases because offering satellite based Internet to residential customers without making them angry while being profitable is hard. So I've no experience with HughesNet Gen4 or ViaSat Exede as products in particular but I know the underling platforms. In general the systems are optimized for fast browsing and VoIP from the own operator. The modems you'll use with the mentioned services will include all kinds of acceleration features. General acceleration of TCP sessions to work around TCP implementation issues in combination the the high RTT (slow start, behavior during packet loss/high jitter, window scaling, ...) are standard for these services. The residential services usually use additional acceleration features like HTTP prefetching/pushing. That's usually done using a transparent HTTP proxy which sits at the teleport analyzing all HTTP requests/responses, download images etc. already before they are actually requested the the end users browser. They are then pushed to the modem which will delivery them as soon as the end user requests them. As a result the end user doesn't have to wait another RTT for the images etc.. Similar sniffing/spoofing acceleration options are available for other protocols. But with end to end encryption becoming more common these days all these transparent higher level acceleration features of the modems, etc. no longer work. Of course you still can do the same but you have to move the acceleration to the client device. That's not very common yet in the satellite industry. Regarding phone conversations our experience is that the high RTT is not that much of an problem in practice. People recognize the delay and wait longer before starting to talk automatically. But the experience might vary extremely depending on the operators config and end devices. You need corresponding QoS settings to keep latency/jitter low and stable. For residential services the return channel will be most likely time division multiplexed. Once the network is congested (=profitable for the operator) you'll see the latency go beyond 1 second more or less often without proper QoS settings. That of course will completely break your VoIP experience. You should expect that the operator only has corresponding QoS settings for their own VoIP service in place. Experience with third party services might suck due to that. Another issue you might run into are some VoIP phones. Some of them only support very small jitter buffers (<10ms) which might cause problems. IPsec tunneling, GRE tunneling etc. should work perfectly fine unless it's intentionally filtered. But as soon as you do tunneling/encryption you should expect that you byepass any acceleration feature or high priority QoS rule. Besides that both products you mentioned AFAIK are using Ka-Band spot beam satellites. There's probably roughly one beam per US state. Assuming 200 MHz per beam that translate to roughly to a maximum of 600-700 Mbit/s downstream capacity shared by all customers in that beam (one state). Upstream is probably designed for half of that. This grouping of customers also makes a simple experience comparison difficult as your experience will heavily depend on the congestion level in your beam. From other similar services we already know that at the launch new customers are happy (always getting the maximum speed) but as the network fills up they get angry due to bad performance during peak times. I really wouldn't recommend a sysadmin to use a geo stationary satellite based connection for your daily work unless there's no other way - simply due to the latency. You'll notice a significant productivity impact. Best Regards, Frederik Kriewitz