Winlink 2000 for ARES: Frequently Asked Questions

Written documents impose their own kind of discipline. They are accurate, may contain graphic pictures or complex drawings, and they may be stored as a permanent record for whatever purpose desirable. The question is not so much why digital, but why the need to complement voice communications, and what format and medium should be used.

The solution to written (digital) communications becomes obvious when we consider that 99.9 percent of our EmComm efforts are in behalf of the agencies we serve. Certainly our agencies do not expect to use Telex. When was the last time you think a served agency sent or received a Telex, or for that matter, a Telegram, MARS Gram or NTS formatted Radiogram? When do you think the last time one of these agencies sent an email? Let’s face it, the world has adopted SMTP Internet email and in order not to appear antiquated when assisting our served agencies, we should not disrupt their pattern by attempting to use any other medium. Rather, we should efficiently and transparently provide them with what they use daily, SMTP email on their own computers, in their own normal operating places with their own familiar email programs.

A quote from the former FCC Director of Engineering and Technology sums it all up:

"In the past, hams have adopted more spectrally efficient technologies - for example, by migrating from double-sideband amplitude modulation to single-sideband modulation and, more recently, by shifting to more efficient modulation for digital modes. I would urge you to continue shifting towards more spectrally efficient communications techniques - especially digital techniques. Such a shift has a number of benefits:

• First of all, it demonstrates to policymakers and regulators that you are good stewards of the public's airwaves even without direct economic incentives.
   
• Second, by using what you have efficiently, it strengthens your case when you need to ask for additional spectrum.
   
• Third, by allowing more users to access the available allocations simultaneously, it improves the amateur experience and ultimately increases the attractiveness of the service to new and old users alike.
   
• Fourth, it provides the opportunity or "headroom" for increases in data rates to more closely match those available on wire line networks and, in the future, on commercial wireless networks as well.
   
• Fifth, as the rest of the telecommunications world makes the transition to digital techniques - and there are very few exceptions to that trend - the amateur service will look antiquated if it is not making progress in that direction as well.

So looking to the future of the amateur radio service in the new century, I would urge you to continue your traditional role in public service by being prepared for and providing communications in times of emergencies, conducting experiments, providing training in radio communications, and encouraging international comity. But I would also urge you to focus particular attention -- for the reasons I just mentioned -- on experimentation with digital techniques."

(End Quote.)

Winlink 2000 is not looked upon as a complement to the other forms of communications now employed by ARES and NTS. It is not meant to be a replacement for such long standing and proven services.

2. How would Winlink 2000 deployment fit into the ARRL Field Services organization?

Winlink 2000 is proving to be an outstanding addition to the capabilities of ARRL Field Services, providing nearly real-time radio email service for all served agencies and the public. It can work in harmony with the resources of the existing manually operated NTS and the NTSD digital services to cover all parts of our country and beyond, with ARES providing the connections to the served agencies within the Sections. Winlink 2000 can greatly enhance the operation of all these combined resources, and is robust in speed, interoperability, ease of use and surviving loss of infrastructure. It can provide those we serve with what they need.

Its four developers, Vic Poor, W5SMM, Hans Kessler N8PGR, Steve Waterman K4CJX, and Rick Muething KN6KB own the Winlink 2000 source code. To date, the Winlink 2000 system has taken approximately 10 man-years of development effort, and the developers do not intend to release it to the public domain. However, the Winlink Development Team understands that deployment of the Winlink 2000 system on a national level with ARRL sponsorship requires assurance that the software has been properly documented and that the source code will be made available to whoever could take over maintenance should it be required. Therefore, the Winlink Development Team has offered to execute a properly worded Escrow agreement that will hold the source code in Escrow with a third party. Such an Escrow agreement will offer the appropriate assurance for continued use of the software should the developers no longer wish to maintain the software. The Winlink 2000 software is not intended for any other purpose other than for the ARRL ARES/NTSD without the prior written consent of the developers.

Winlink is continually being documented, and such documentation will be included with the Escrowed source code. Ideally, the Escrow site would be a secure FTP site, hopefully sponsored by the ARRL, where the developers could keep the source code and documentation up-to-date.

There is a separate issue with Airmail that is copyrighted by another individual who also sells this program outside the Amateur Radio community. Jim Corenman, KE6RK, has been making Airmail available at no charge to the Amateur radio community. Several non-Amateur carriers also license airmail for commercial use. However, Jim Corenman has agreed to follow the Winlink Development Team in its agreement to place its software source code in Escrow with the same constraints regarding other uses.

4. When directly connected to the e-mail system of a served agency, how can we ensure that the message traffic complies with Part 97 rules regarding message content?

Winlink 2000 employs multiple mechanisms to insure compliance with Part 97 content rules, however, remember that when Sub-Part E is in effect for any real emergency, it also applies. Regardless, the following steps are taken to insure Part 97 applies:

• Virus Email screening on all inbound and outbound messages. To date, no infected file from a virus has ever successfully entered the Winlink 2000 system.
   
• Inbound E-mail is allowed only from trusted senders via a globally maintained "acceptance list" http://winlink.org/accept. Trusted senders are those that have received mail from Winlink 2000 radio users, or who are otherwise specifically placed on a trusted senders list. Normally, Internet users may manually temporarily register their email address from the web for a period of only 5 days, or until a reply has been sent by a Winlink user. Should the Winlink user reply within the 5-day period or initiate the communications, the address remains valid for 6 months from the date of the last reply.
  
  For ARES, this feature may be easily turned off or on, depending on the specific situation. The acceptance list methodology is employed by many major ISPs to keep unwanted email away from the Winlink 2000 user.
   
• Winlink 2000 maintains a "do not accept" list that can block any specific Email address or radio user. Each and every radio users has a "Permissions" status that allow operations on only those bands that the license dictates.
   
• Internet and Radio users are continually advised and educated regarding content and traffic limitations of the system to comply with Part 97. As a matter of policy, we also include those non-US Amateurs users who have no USA FCC affiliation as well as Amateurs in International waters.
  
  For ARES use, it would also become a responsibility of the serving ARES community to educate those individuals in served agencies who have access to the Winlink 2000 system during normal periods to have some understanding of what is allowable traffic.
   
• Winlink 2000 sysops and administrators do routine message content review of messages that go over the Amateur Radio spectrum. Any content found to be illegal or questionable is removed and the sender given one warning. Repeat offenders are locked out of the system. The responsibility for monitoring content for ARES use would fall on the control operator of the ARES serving stations just as it does with any other Amateur operation.
   
• Winlink 2000 utilizes real-time network monitoring for its servers and participating stations http://winlink.org/status. As the network delves into more of an emergency management mode, password security for the network status may be easily employed.
   
• New radio users are given a short time period in order to receive verification of their proper license. If none can be found in a country’s official database, the user is given 7 days to fax it to the Winlink administration or be permanently locked out of the Winlink 2000 messaging system. Again, it would appear that the serving ARES community would assure that their operators have the appropriate license for operation of the various components of the Winlink 2000 system.

Winlink 2000 has been operating since 1999 under close scrutiny and without incident.

5. How long does it take to become a subscriber? Can the system be positioned so that it's available when an agency needs it even though the agency has not done any deployment work or training in advance of the onset of an emergency?
 

The setup and operation of the Winlink 2000 system is straightforward and radio users are automatically registered upon an RF connection to the Winlink 2000 system. However, like any system it requires training of operators to set up and become familiar with the various software programs and operational modes. In addition specific "Internet bridging" mechanisms being discussed require the proper setup at each end of the link to insure reliable operation in the case of loss of Internet connectivity.

If the system is to operate reliably during an emergency it must be operated, tested and maintained continually, and users and operators of the system must be familiar with the programs and techniques used to send mail via RF radio/internet links through the Winlink 2000 system. This is the ‘added value’ that radio amateurs bring to the table.

During an emergency, the end-user in a served agency does not need special training other than perhaps some information regarding message content. With the Winlink 2000 Paclink module placed on a served agency computer, those not familiar with ham radio or digital communications may transparently use the Winlink 2000 system with their own email programs on their own computers in their own offices if they are set up properly and given information about speed of delivery and attached file limits. The Paclink module was specifically designed for this purpose. The only difference to an end-user in a served agency is that the EmComm email account using Winlink 2000 may be slower than a normal email connection since it will be over Packet Radio rather than their normal connected service.

6. Are binary attachments legal?  

The Winlink 2000 "B2F" protocol has no encryption and may use standard publicly documented modes such as AX.25 Packet or Pactor. Binary compression and file transmission have been used extensively by radio BBS systems for many years, and been ruled permissible since they do not violate the encryption rules. Actually, there are no differences in protocols between attachment email and non-attachment email.

7. Does Winlink 2000 contain any redundancy measures? What if the Internet fails in the immediate area? How robust is Winlink 2000 What is its experience thus far as a reliable system?

Winlink 2000 is a network system integrates or bridges RF radio and Internet connectivity. Over the Internet, the system behaves like any other Internet communications system and can handle any type of Internet connectivity such as wireless routing (802.11b/802.11g, etc) or satellite communications, cell phone, etc.

In order to send and receive seamless, end-to-end email to single or multiple recipients, with single or multiple copies, and with multiple binary or text-based attachments, Winlink 2000 utilizes the binary "B2F" protocol. There is a provision for utilization of much more limited protocols, but with much less proficiency, security and reliability. The B2F protocol then, may be transferred via any Internet connectivity methodology. Pactor, Packet, TCP/IP, etc., may all be wrapped around the B2F protocol.

The B2F protocol also is adaptable to higher speed radio modes such as AX.25 Packet, the Pactor modes, and other such complex higher speed ARQ modes. On HF, the Pactor 2 mode may be employed to provide up to 800 Bits per second, the Pactor 3 mode up to 3600 BPS while on VHF/UHF, from 1200 to 9600 baud or greater (same as bps for Packet) Packet may be used.

With nearly 44 percent compression and excellent error correction, the B2F protocol is a superb means of linking the radio user to the Internet. Nothing has yet been discovered that is more robust, and should it be found, it will be used. Likewise, should a more robust or efficient mode be discovered to wrap around the B2F protocol, we will certainly be using it.

Winlink 2000 uses a "Star network" topology with two central redundant servers, called "CMBOs" or "Central Mailbox Offices." There is an Eastern U.S. CMBO and for redundancy, there is a West Coast CMBO. Each is located in a secure site with backup power. In addition, the network nodes, or participating Winlink 2000 network radio stations, are called "PMBOs" or "Participating Mailbox Offices." Users, then communicate with the PMBOs either directly or through other modules, depending on the scenario.

Each PMBO has HF connectivity ability that can cover several frequencies on several bands via a scanning module that controls the radio. Each PMBO has an ability to integrate into a VHF/UHF Packet network. On a side note, think VHF Packet is dead? Take a look at what is happening in Florida, and you may be surprised at what has been resurrected since the Internet has become so available. A good example may be found at http://www.fadca.org/map/index.html.

Each PMBO has an ability to be a Telnet Server that allows local or distant Telpac nodes, as well as Paclink and Airmail modules to send and receive messages over the Internet instead of the radio. Not all PMBOs use all these abilities, but most participate so that the network is optimal for the 5,000 plus users who depend on it daily for their communications needs.

For Emergency communications, each PMBO with a co-located VHF/UHF Telpac node has the ability to hub all digital radio traffic that passes through it. This would include VHF/UHF as well as HF email traffic. It will also continue to work perfectly regardless of the loss of the Internet as long as those communicating are hubbing through the local EmComm PMBO. This means that the local served agencies can send each other email, as well as email the field, all without any local Internet capability. Two such examples are now being employed in Harris County (Houston, TX) and for the State of Michigan. However, their operational characteristics are no different than any other normal PMBO. The only difference is that these PMBOs are not published or "non-public" and are not listed for everyday service. Rather, they exist for ARES purposes only. We anticipate adding many more of these type participating hubbing PMBOs. The more there are, the less will be the load on the public PMBOs for EmComm. Incidentally, there are over 180 Telpac nodes in existence as of this writing.

As far as the history of the system, below is a quote from SAIL Magazine, May 2002, "HOOKING UP with High-Frequency E-Mail" by Charles J Doane:

"By far the most popular HF e-mail service for recreational mariners is the amateur ham network known as Winlink 2000.  In many respects it is also the most sophisticated system available anywhere today.  Winlink has the most robust software, the most mailbox stations standing by to route traffic into the Internet--31 volunteer stations at last count, scattered literally all over the world--supports multiple attachments to messages, can be accessed via landlines, has a position-reporting feature that allows family and friends to see from where a Winlink user last hooked into the system, and offers a variety of weather products that can be downloaded from the system's bulletin board. Best of all it is totally free.

All in all, it is probably one of the most impressive congregations of volunteer technical talent seen anywhere in communications today.

For cruisers who want to achieve maximum range and flexibility at minimum cost, Winlink is a must.  Obtaining a ham license has other benefits, as ham networks can patch voice calls to offer invaluable support in emergencies."

(End Quote.)
 

Other such statements in many articles describing the power of Winlink 2000 and its effectiveness as a communications system may be found on http://winlink.org/news.htm.
 

8. Is the VHF/UHF Packet portion of the Winlink 2000 system compatible with other existing packet networks?

This depends on what is being used. As a general rule, as with any vertically layered network topology, the feature set of the entire system is only as strong as the weakest component within the network. If an existing digi is employed, it will most likely work, but it will cut the throughput in half. If a switch is used, the switch may come in at one speed and leave at another speed depending on the type of switch and its configuration. Like a digi, nodes may also slow digital communications. What should be replaced to keep the feature set described above, including end-to-end seamless email to multiple recipients with multiple attachments is the Packet BBS. A Telpac node should replace such a BBS to maintain functionality. We know of no current BBS that will allow this functionality pass. In addition Packet style "H-Routing" may be employed to the PMBO level, but again, with a significant loss of functionality. Remember, we are serving agencies that do not particularly care to move away from their standard and long time adopted SMTP mail.

Catalog: Winlink 2000 has a Global catalog list that contains over 700 weather products and a large "how to" help section. There is also a provision in each PMBO for local information such that is particular to each participating station. For ARES, such bulletins would and should contain operational or procedural information for the ARES teams as well as required information for the served agencies. This information may be text-based or contain binary file attached information.

Position Reporting: Winlink 2000 contains several Graphic means by which users may be tracked if so desirable. There are three graphic methods, including APRS and one email request method. In addition, each Airmail client has the option of turning on a manual or automatic tracking system, which works in conjunction with a small portable GPS that is interfaced into Airmail program. Manual input is a lesser attractive option.

Flexible message routing is employed. There are two classes of users, Fixed and Mobile. A user set to a "Fixed" status is routed to a single participating station (PMBO.) Therefore, all messages go to that PMBO. However, a fixed user may place messages on the system from any PMBO.

A Mobile (default) user has the ability to check into any PMBO. When the user checks into a specific PMBO, messages will go to that specific PMBO for a duration of 90 days from the date of the last check-in. If a user checks into n number of PMBOs, messages will go to those PMBOs under the same conditions. Each PMBO is transparent to other PMBOs in the system, so that the user may pick up part of the messages on one PMBO and when they check back in on another PMBO, only those remaining messages will be pending. This process is also true for Global Catalog items and Position Requests.

Plans for the Winlink Development Team are to code an enhanced version of both the CMBO and the PMBO in order to provide more redundancy and less Internet dependency. Specifically, plans include replacing the current CMBO servers with redundant synchronized servers called "CMS" or "Central Message Server." There will be multiple CMSs, which will be distributed in such a way so that they will not be within the same geographical region. Their specific numbers will depend on the size of the Network expansion. In addition the current PMBO will be replaced by the "RMS" or "Remote Message Server" and will be able to route randomly to any one of the CMSs. In addition, the new RMS will be able to alternate route over HF radio when the Internet fails. Radio routing is also planned for an alternate route for Telpac. The time frame for this is not definite, but we have started the migration. It will not have an effect on any current operational functionality.

In sum, The Winlink Development Team is has developed an existing, reliable, redundant digital communications system for the mobile or fixed user with or without Internet access. It currently hosts over 5, 000 HF radio users and over 56,000 Internet recipients who pass over 150,000 messages using over 260,000 radio minutes through the system monthly. The average size of each message is approximately 5600 bytes and the average total connect time throughput is approximately 1.8 minutes. The average time for a message to be sent from an Internet recipient to a PMBO for pickup is approximately 1.4 minutes. This is not anywhere near capacity since the system resources are barely being used. In addition, these numbers do not include the ARES uses of Telpac over Telnet or the WEB browser access to the system.

The Winlink Development team has recently shifted gears and is now enhancing the system to be more easily employed as an emergency management tool for community served agencies, with an ability to link anyone, anywhere, locally, regionally, nationwide or Worldwide. Remember, this is a proven, working, operational system and does this currently, many, many times daily, every day for its current users, just about everywhere in the World.

The Winlink Development Team

       Vic Poor, W5SMM

       Rick Muething, KN6KB

       Steve Waterman, K4CJX

       Hans Kessler, N8PGR