If you are a corporation in crusade of disaster rescue networking solutions, a first responder who may need connectivity from everywhere at any time, or you simply need broadband internet connectivity from remote locations you have probably carefully that satellite may be your only trustworthy option. In the midst of a disaster many businesses and first responders may find themselves without communications of any kind due to the loss of terrestrial infrastructures, or the lack of it ever existing in the first place.
The question is that most enterprise professionals and crisis assistance workers do not have a faultless insight of the satellite enterprise and the idiosyncrasies of communications via satellite, and why should they? Satellite communications is not their profession. In the quest for a satellite internet assistance provider there are determined questions you should be ready to ask before you get locked into a contract for services that won't satisfy your needs:
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1) Do you have Non pre-emptible satellite space segment?
Satellite operators such as Ses Americom, Intelsat among others lease space segment to satellite assistance providers. There are distinct levels of protection available in varying price ranges. Many assistance providers will opt to contract for pre-emptible space segment because it's much less costly and they can make larger profit margins which they may or may not pass on to their end users. Pre-emptible space segment gives the satellite operator the capability to deny way to the satellite for the assistance provider in the event of an on board equipment failure, or to make room for a assistance provider who is willing to pay the Non pre-emptible premium.
During large scale disasters such as the hurricanes in the Gulf States in 2005 many pre-emptible segments of satellite space were cleared to make room for government requests for satellite assistance leaving other assistance providers with no access. If you are considering contracting for assistance for disaster rescue applications it is very recommended that you find assistance providers that warrant that they have contracted for Non pre-emptible space segment. The assistance provider should be able to contribute you with evidence of their assistance deal with the operators if you ask. You may pay a minute more each month for your non pre-emptible service, but at least it will be available when you most need it.
2) What is your "Over Subscription" or "Contention Ratio"?
Most satellite assistance providers who are providing Internet services are operating systems that use Tdma (Time division complicated Access) based systems. A Tdma law is normally controlled by a central hub location which will command the remote units in the field to forward their data when the hub is ready to receive it. This allows for many remote units to share the same slice of bandwidth improving the allembracing efficiency of the system. The transmissions from the remote units are sequenced at a very high rate, many times per second, which makes the assistance appear to be continuous.
However, the more units that are added to the system, the slower the assistance will be. A true enterprise level operator will never allow their contention ratio to exceed 20:1 or essentially 20 terminals per segment of bandwidth. Many operators that offer lower grade services will over subscribe their systems as high as 40, 80, 120:1 or more. Some operators may not be willing disclose this information to their end users. If a assistance provider will not tell you their contention ratio, you might reconsider looking elsewhere as their ratios are likely to be high. This will directly work on the capability of the assistance you receive. enterprise level operators with contention ratios of 20:1 or less will payment more for their services since they have fewer users for their contracted space segment. But, you get what you pay for.
3) What is your law Latency, and does your hardware or software contain Tcp/Ip acceleration?
Any Ip transport platform will have a determined amount of latency that is inherent to the buildings of the system. Latency is normally measured by how long it takes for a Tcp/Ip "Ping" to be sent to a server on the other side of the transport link and be returned back over the link to the point of origin. Satellite systems, due to the physics complicated will have much higher latency figures that any terrestrial link. Data is transmitted to the satellite at the speed of light, or 186,000 miles per second. The satellite is located 22,223 miles above the equator.
For a ping to make its round trip it must voyage up to the satellite, back to earth to the server, up to the satellite again and back to the origination point. This is a round trip is practically 88,892 miles. When calculated with the speed of light, in a exquisite world the round trip will take about 448 milliseconds. When you add in coding delays and processing delays you can growth that shape by 100 to 250 milliseconds. On an sufficient system, a round trip ping should take in the middle of 550 and 700 milliseconds (225 ms one way in each direction).
Many lower grade systems on the shop today will in fact return ping times of 1200 milliseconds or greater which is too slow to allow for functionality of determined software applications. Some law operators have added Tcp/Ip acceleration products to their equipment. This can whether be a hardware or software solution. Acceleration of Tcp/Ip does not speed up the actual transmission as it is already being transmitted at the highest speed possible, the speed of light. The acceleration is achieved by modifying the Tcp protocol in ways that allow for more sufficient transmission over high latency networks such as satellite. Acceleration can significantly heighten the speed of loading web pages, so it is a very desirable product to have. Most of the products are not capable of accelerating encapsulated data such as Vpn's, but the law should still pass that data, however more slowly. Be sure to ask whether or not the law has an acceleration product included.
4) Does your law keep VoIp, Vpn, and Streaming Video transmissions?
If you have determined applications that you intend to operate, be sure to interrogate whether or not these applications are supported on the system. VoIp (Voice over Ip) for telephone connectivity is becoming a very tasteless need in satellite communications. All types of users from crisis services to enterprise continuity are asking for telephone connectivity. The biggest concern most prospective users of VoIp over satellite have is that the latency will be too high for sufficient voice communications. This has largely been proven to not be true. In fact, most cellular telephone systems will sense as much or more delay in their systems than VoIp over satellite. Most satellite providers will keep these systems, but if the law latency is more that about 800 milliseconds, you may sense mystery carrying on a conversation. Some assistance providers will also sell VoIp equipment. If you pick to purchase from them, or on your own you will want to make sure the equipment includes good voice compression.
Most off the shelf VoIp systems that are not designed for use with satellite will occupy in the middle of 40 Kbps and 90 Kbps of bandwidth to faultless each call. If you purchase 128K of satellite uplink bandwidth you may consume all of your bandwidth with one or two phone calls leaving none for internet way for your computers. There are compression VoIp systems available that have been designed for use over satellite that will use as minute as 8 Kbps per phone call and the call is toll quality. There are even compression systems that will allow for a 1544 Kbps T1/Pri connection over less than 256 Kbps of satellite bandwidth. You will also want to interrogate about connectivity to the Pstn (Public Switched Telephone Network). When the signal lands at the hub it will need to connect your VoIp traffic to a telephone line. Some assistance providers will contribute this assistance for a fee; some will not contribute it at all, so be sure to ask. If you need to control a Vpn over the system, keep in mind that it will likely not be accelerated over the satellite.
Acceleration of Vpns can be achieved with external hardware; however it is normally up to the buyer to contribute that equipment. There are some systems, mostly buyer grade, that will not keep Vpn's at all or there are added charges so be sure to ask. The same goes for Video transmissions from a streaming device, or a web cam. Video streams are very bandwidth laberious applications and most assistance providers will wish dedicated bandwidth for these applications. The pricing for dedicated bandwidth will be substantially higher than the shared ratio pricing as it consumes 100% of the bandwidth 100% of the time. If you are planning to stream video to complicated receive sites it is recommended that you stream the video over the satellite to a server, and allow other users to get the stream from the server. This way there is only one active stream over the satellite where the bandwidth is expensive.
5) Do you offer Cir or Cra services?
Cir (Committed information Rate) and Cra (Committed Rate Assignment) are distinct acronyms with the same meaning. It is dedicated satellite bandwidth that is normally required by the assistance provider if you intend to control high bandwidth applications such as video streaming over the satellite. Most enterprise level assistance providers offer Cir/Cra packages, most buyer level operators do not. The pricing for these services will be significantly higher than shared ratio services, so be prepared. Some providers also wish Cir/Cra services for VoIp. Be sure to interrogate if this is something you need as some operators may not volunteer this information until it's too late.
6) How many group Ip addresses do I get?
Many buyer level services do not assign group static Ip addresses for you to use. This is primarily why they don't keep services such as VoIp and Vpn. enterprise level providers normally contribute at least one address, some will contribute more. Most providers will give you a fixed amount of addresses with your assistance and payment you if you want added static Ips. The recommended way to avoid the added charges is by using your own router on the law and natting your own addresses. Some systems will not keep natting so be sure to interrogate if this is what you need.
7) Do you have a Fap?
A Fap or Fair way course is a set of rules that you agree to abide by when contracting for their services. They also will contain determined restrictions on your service. Read this course very carefully as the providers like to contain wording that can seriously restrict your usage. Some assistance providers will "meter" your throughput on the system. If you reach a determined level of usage, normally recorded in Kbps, or Mbps they may restrict your bandwidth to a low level, or cut off your assistance entirely until the next billing cycle. It is very difficult to portion your own usage since most citizen have no Idea how many Kbps are sent or received when loading a web page. The Fap is also where the provider will spell out the rules of usage about applications such as streaming video and VoIp. Going over that document with a fine toothed comb will be in your best interest.
8) What will be my actual measured speeds?
The assistance providers will sell you a specific rate plan that will have an uplink or return data rate, and a downlink or forward data rate. This will normally be expressed in a manner such as "128/512" or sometimes "512/128". The larger amount will always be the forward channel which is your downlink as a user. Most providers will not tell you that the speeds contain Ip overhead. Every internet law whether its satellite or terrestrial uses Ip protocols that wish a determined amount of bandwidth to process the Ip traffic. Because of the overhead you can expect that your actual measured payload speeds will be nearby 20% lower than what you are paying for. Actual speeds can be measured by running a speed test from a Pc over the satellite link.
If the assistance provider has their own speed test server at the hub location this will give you a more definite test of the satellite link than an Internet based speed server. The internet based servers have too many variables to get definite results since the data is being transferred over connections that are not under your control, or theirs. Most systems will be similar in their Ip overhead usage, but be aware of this when you purchase your service. If you don't think the speeds will be high sufficient when you factor in the 20% overhead you may want to reconsider a higher assistance level plan.
9) What Pricing plans do you offer?
In your crusade for a assistance provider you will likely encounter a multitude of pricing plans. Each provider will generate pricing structures that meet their enterprise model, and that will give them an edge over their competition. Because of this you may find it difficult to correlate price. All providers will offer full time 24x7x365 assistance plans. Some will also offer plans based on usage, and some will sell daily or hourly plans. There are even providers that will sell assistance for a fixed amount of days each month. These plans can be absorbing as you will not likely use a law designed for disaster rescue every day of the month, so why should you pay for full time service? If you are comparing price in the middle of providers it is easiest to look at their full time rates to rule the cost. However, keep in mind that operators base their pricing on their cost for the satellite space segment. If they are charging less it may be because they don't have non pre-emptible space or because they control with high contention ratios, or both.
10) Do you offer other services such as terrestrial connectivity and collocation?
Be sure to interrogate about value added services such as collocation space and terrestrial connectivity. Unless you are only buying internet way and have no need for VoIp, streaming, or data backup, you will likely need these services. Some assistance providers will contribute connectivity to the telephone network, and some will not. If you need dial tone you will probably want to contract for that as well. For disaster rescue solutions it is very recommended that you generate your dial tone from a safe location that is far away from the affected area.
In many disaster scenarios the terrestrial connectivity including cellular phones will not be available. It is leading that this is taken into list when designing a backup network. Some of the satellite providers will also offer services to back up corporate or government server data at the satellite hub location. This is very beneficial to the buyer as it provides both off site warehouse of vital data, and easy way to that data via the satellite when it is most needed. A satellite hub with a collocation installation can be a fine tool, and should be very carefully when contracting for satellite services.
Top 10 Questions to Ask Your Satellite Internet service victualer
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