You need to contact Jetcoms marketing, fill the application form and pay the registration fee.

You need an Ethernet card, hub, switch or router to connect your computer to our network.

For redundancy we are connected to tier one Internet backbone provider using fiber optics and VSAT.

Our network based on point to point dedicated type connection technology. Cable modem network based on shared type connection with broadcast technology that has a topology called tree branch. As a result, as the cable modem’s subscriber increase in a ring, the speed decreases substantially.

The shared broadcast network cannot sustain the connection speed since it depends on the availability of the bandwith. The return channel also substantially very limited since the broadcast technology uses much of the bandwidth available for broadcasting.

Typical users for cable modem network are individual that are browsing and downloanding. The typical users for point to point dedicated network are corporation that are downloading and uploading data, video conferencing etc.

Yes, we are directly connected to the IIX.

For the best service you should get Jetcoms Linux Gateway Server as the proxy server to be able to share the Internet access to all the PC.

Based on our experience there are many possibilities:

1. Network problem: based on our experience many client’s network was not designed properly. Many uses hubs instead of switches. There are usually bottle neck in the network.
2. Gateway server problem: based on our experience our Jetcoms Linux Gateway Server’s speed outperform any other gateway server such as: Winroute, Winproxy etc. Also gateway server should not be used for other means.
3. Testing problem: many test are conducted by using a direct dial up connection against JetcomsNET connection behind gateway server that is not Jetcoms Linux Gateway Server.
4. Testing time problem: many test are conducted in different time. Time difference will have test server’s load differences and Internet link quality differences.
5. Test load problem: test should be conducted to download a file with relative size, not just a page.
6. Windows default setting problem: Windows operating system has default setting in its system set up for dial up users. To get the benefit of broadband connection user should tweak the TCP/IP.

TCP is a reliable communication protocol. As a result, sender expects Acknowlegement (ACK) packets from receiver to make sure packets are delivered to destination and are free of errors. However, as sending one packet and waiting for ACK is rather inefficient, a window is implemented. In this scheme, receiver advertises its RWIN size during TCP connection setup and sender keeps sending as many packets as allowed by receive window of receiver. In other words, each packet sent closes the window a little and each ACK received opens it up a little again.
On a high bandwidth or high delay (or both simultaneously) TCP connection, sender may transmit a number of packets before the first packet reaches the receiver. Even if the receiver were to send ACK immediately, it takes some more time for the ACK packet to get back to the sender. To optimize the throughput, the pipe must be filled at all times and to do this sender should never stall waiting for ACK.This is only possible if Receive Window is made sufficiently large.

The most significant parameter for TCP/IP tuning is the TCP Receive Window (RWIN). Most other tuning attempts usually do little or no benefit and may actually cripple proper TCP/IP connectivity as exemplified by so called MTUTweak programs that aim to optimize the line for dial-up use. If you have previously used one of these programs, I suggest you remove the registry changes done by them. Typically, these programs lower your MTU (maximum transmission unit) to 576, reduce TCP Window Size to as low as 2144 (an absolute no no for broadband connections), Disable Path Maximum MTU discovery (when this is diabled windows uses an MTU=576). After cleanup download one of the following registry files and double-click to import it to the registry. You must reboot to get registry changes effective. Note that except Window 2000 the default for RWIN for Windows family is ~8KB. Windows 2000 uses ~16KB as default RWIN.

OS Small (16KB) Medium (32KB) Large (64KB) Huge (128KB) Windows 95* rwin95-s.reg rwin95-m.reg rwin95-l.reg N/A** Windows 98* rwin98-s.reg rwin98-m.reg rwin98-l.reg rwin98-h.reg Windows NT*** rwinnt-s.reg rwinnt-m.reg rwinnt-l.reg N/A** Windows 2000*** rwin2k-s.reg rwin2k-m.reg rwin2k-l.reg rwin2k-h.reg

* For Windows 95 with Winsock 2.0 or DUN 1.2/1.3 update use Windows 98 registry files. ** Windows 95 (without Winsock or DUN update) or NT does not support RWIN > 65535. *** Use a user account with administrative permissions to be able to change registry.

The chart below shows you the various optimal sizes for DefaultRcvWindow, depending on your line speed, and your Ping time, as calculated as the average of ping for large (say, 1400 byte) packets, and ping for small (default ping) packets. Read off your DOWNLOAD line speed to the left, and across the top, the average ping time calculation for the servers you typically talk to. Colors indicate where the default setup of Windows 95/98 or NT is not sufficient.

Line Speed Bandwidth Delay Estimate 10ms 50ms 100ms 150ms 200ms 300ms 500ms 128kbit 160 800 1600 2400 3200 4800 8000 256kbit 320 1600 3200 4800 6400 9600 16000 512kbit 640 3200 6400 9600 12800 19200 32000 784kbit 980 4900 9800 14700 19600 29400 49000 1024kbit 1280 6400 12800 19200 25600 38400 64000 2000kbit 2500 12500 25000 37500 50000 75000 125000 3000kbit 3750 18750 37500 56250 75000 112500 187500 6000kbit 7500 37500 75000 112500 150000 225000 375000 this = Large TCP Window Support Required this = Larger than default window size for Win 2000 this = Larger than default window size for Win 98/NT

Experiment with different RWIN to find the best setting for your connections. Remember to reboot after each change and test with a site that is typical site that is 10-15 hops away as RWIN depends both on bandwidth and latency characteristic of the line. Making RWIN too large may reduce throughput especially on a line experiencing packet loss. When the line is experiencing significant packet loss RWIN may need to be reduced even further. This is because smaller RWIN size allows for faster recovery of lost packets.

Receive Window should be larger than bandwidth delay product (also known as pipe capacity).

For example, for 170ms delay on a 768Kbps link, RWIN = 768000 bits/sec * 0.170 sec = 130560 bits = 16320 bytes.

Note that if either available bandwidth or the delay is doubled, RWIN would double as well. On LAN links the delay is very small. Therefore, a small RWIN would be sufficient. However, effect of insufficient RWIN size become particularly noticeable on WAN links. Due to relatively small default RWIN size (8KB) Windows 95, 98, NT 3.51 and NT 4.0 throughput would suffer in above 768Kbps connection during file transfer via FTP. Windows 2000 uses a more realistic 16KB default for RWIN. However, that too would need to be increased depending on pipe capacity.

Well, that looks rather simple but latency (delay) is actually not constant. It varies from connection to connection and even during the lifetime of one connection as some IP packets may follow different routes and the heavy load on a router in the path may cause extra latency.

Latency consists of two parts; Propagation delay and transmission delay. Propagation delay becomes significant for links established over satellites and transmission latency becomes significant when the packets must be forwarded over many routers. In addition routers usually introduce more latency for larger packets than smaller packets. Generally, heavy traffic in the pipe also increases transmission delays.

To determine delay accurately we actually need to measure downstream and upstream delays separately because we receive large data packets on downstream and generate much smaller ACK packets on upstream. This measurement can be most effectively done on the sender side. However, we can make an intelligent guess on the receive side by using the PING tool to determine the round trip time for big (maximum data packet sized) packets.

Windows 95/98, Windows NT 3.51/4.0 and Windows 2000 comes with a command line tool called "ping.exe". Open a command (DOS) window and enter the following line:

ping -f -n 10 -l 1472 host_or_IP

Use (MTU - 28) as the parameter for -l option (e.g. for ethernet use 1500-28 = 1472). See Microsoft KB article Q159211 on using PING tool to determine MTU (see More Information Section). Even though the article is targeted to Windows NT, this portion of the article is general enough to apply all Windows OS and the concept is applicable to other OS easily. In short, this parameter should be the largest value that will NOT generate "Packet needs to be fragmented but DF set." message.

Large packet delay measured using ping tool is the worst case delay, so it sets the upper bound for RWIN. Most certainly normal delay will be smaller as ACK packets used in return path will be much smaller and typically delayed less. We may make a rough guess of typical delay by averaging ping times of large (as above) and small (ACK sized) packets. For ACK sized packets use 12 as -l parameter as in:

ping -f -n 10 -l 12 host_or_IP

Example: A 608/128Kbps DSL link with 200ms for maximum sized and 100ms for small packet delays:

RWIN(max) = 608000 * 0.200 = 121600 bits = 15200 bytes.
RWIN(typical) = 608000 * 0.150 = 91200 bits = 11400 bytes.

Then edit the registry file maching your OS using a text editor such as Notepad and do the following customizations:

Windows 95: Find the following line and substitute RWIN for xxxxxxxx as 8 digit hexadecimal number. You may use Windows Calculator (in scientific mode) to convert decimal number to hexadecimal number. Remember to prepend 0's to make value 8 digits long.

"DefaultRcvWindow"=dword:xxxxxxxx

Windows 98: Find the following line and substitute RWIN for nnnn as a decimal number.

"DefaultRcvWindow"="nnnn"

Windows NT/Windows 2000: Find the following line and substitute RWIN for xxxxxxxx as 8 digit hexadecimal number. You may use Windows Calculator (in scientific mode) to convert decimal number to hexadecimal number. Remember to prepend 0's to make value 8 digits long.

"TcpWindowSize"=dword:xxxxxxxx

Hub shares the internal path for all the ports while switch has a dedicated internal path for every ports. This way switch doesn’t have queing problem as in hub.

You need to contact our marketing and pay for survey fee to get your place surveyed for line of sight and live test. If the test is ok then you have to buy the Customer Premise Equipment and pay the registration fee.

We use the latest state of the art wireless broadband technology.

The speed testing softwares are made for indicative purposes only. And the speed of the connection is depends on the service subscribe, i.e. sharing or dedicated.

In sharing your share your Internet connection with others. Typically there are 5 to 8 other users in the group that share your connection. In dedicated service you have a dedicated rasio Internet connection to the Internet backbone.

Internet is a global network connectivity. Connection between servers and users can be fast or slow depending on the global network status and servers load.

Based on our experience there is a problem in your internal network. Mostly the culprit is the usage of hub instead of switch.

Speed	Sharing Type PC	Dedicated PC
128 Kbps	10	100
256 Kbps	20	200