Isode Constrained bandwidth Whitepapers
On this page you'll find whitepapers which address the problems of operating messaging and XMPP services over constrained bandwidth connections such as HF Radio.
|Deploying IRC, Federated MUC and XMPP Guards
Military communication makes extensive use of text chat services, in particular those using IRC (Internet Relay Chat) and XMPP (eXtensible Messaging and Presence Protocol). The primary approach is use of group chat services to share information. These services are often deployed in hostile environments, and so it is important that they are resilient and will continue to operate when elements of the service fail. Communication needs to operate between partners and across security boundaries (Cross Domain).
(14th May 2013)
|Using Flow Control and Timers in ACP 142 to provide Optimized Message Transfer of HF Radio
This White Paper looks at message transfer over HF Radio, and looks at how the ACP 142 protocol can achieve optimal performance, and the use of flow control and timers to achieve this. HF Radio can be an unreliable channel, and so it is important that performance is optimized in the event of channel failures. Use of timers to deal with failures is considered in detail.
(30th July 2012)
|Federated Multi-User Chat: Efficient and Resilient Operation over Slow and Unreliable Networks
XMPP (the Internet Standard eXtensible Messaging and Presence Protocol) Multi-User Chat (MUC) is normally provided by a single server, with clients accessing a MUC Room via their local XMPP servers. This standard approach gives performance and resilience problems when operating over constrained networks. This paper looks at how federating the MUC service can address these problems. Isode's approach to Federated MUC as implemented in the M-Link XMPP server is described in the context of evolving XMPP standards, and benefits of Federated MUC for purposes other than Constrained Networks are considered.
(6th Sept 2012)
|M-Link & XMPP Performance Measurements over HF Radio using STANAG 5066 and IP
This paper describes and analyses measurements made operating XMPP over HF Radio, using HF modems and a simulated radio link. This paper looks at measurements operating directly over STANAG 5066, and operating over IP. The measurements show that good performance is achieved over HF using STANAG 5066 for a wide range of parameters. Operation over IP over HF gives good results in some situations, but is not generally recommended.
(27th Sept 2010)
|M-Link & XMPP Performance Measurements over Satcom and Constrained IP Networks
This paper describes and analyses measurements made operating XMPP over a slow IP link with variable delay to simulate Satcom. These results are applicable to use of XMPP with any constrained IP network. This paper compares measurements of standard XMPP and Isode's optimized server to server protocol. Comparison measurements with IRC (Internet Relay Chat) are also given.
(13th July 2010)
|M-Link Support for XMPP over Constrained Networks
This paper looks at how M-Link, Isode's XMPP server is optimized for operation over constrained networks, including Satcom, HF Radio, and other Radio links. The paper starts by looking at the benefits of using XMPP over constrained networks, and the key problems faced. Then it describes the M-Link architecture and how it addresses the various problems, both for networks where IP will be used, and for HF Radio.
(25th June 2010)
|Performance Measurements of Applications using IP over HF Radio
This paper sets out the results of measurements made when running applications and layer protocols to support applications over IP via HF Radio using STANAG 5066. The goal of this work was to get a quantitative measure of the performance impact of using applications running over IP over HF Radio in comparison with applications running directly over specialized HF Radio protocols. This paper concludes that the performance impact of using IP is massive, with small message latency increase from at typical value of 6-20 seconds using applications optimized for HF to a smallest measured value of 89 seconds when using IP.
(3rd September 2009)
|Performance Measurements of Messaging Protocols over HF Radio
This white paper sets out and analyses the results of a measurements of various messaging protocols over HF Radio. HF Radio has unusual performance and reliability characteristics, which has led to specific application protocols being developed. This paper finds that three of the four protocols analysed perform well. It concludes with a discussion of the best choice of messaging protocol for various types of deployment.
(5th Aug 2009)
|STANAG 5066 Performance Measurements over HF Radio
This white paper sets out the results of measurements done by Isode of STANAG 5066 over military HF Modems and emulated HF Radio. These test show that good line utilization can be achieved (83-94 %) for speeds ranging from 75 bits/second to 9600 bits/second. To achieve this, care must be taken with how the application uses STANAG 5066.
(9th Jun 2009)
|File Transfer by Email
File Transfer by Email can be useful for moving data between systems when standard file or data transfer mechanisms are not available. In particular it is useful for supporting Directory Replication, as described in the Isode white paper Directory Replication by Email and over 'Air Gap'. This paper looks at requirements for File Transfer by Email, and describes the architecture of Isode’s solution.
(27th Jan 2009)
|Operating XMPP over Radio and Satellite Networks
XMPP, the Internet Standard eXtensible Messaging and Presence Protocol is being widely adopted for Instant Messaging (IM), Group Chat and Presence services in military networks. This paper starts by looking at the military tactical requirements for IM, Group Chat and Presence. It discusses briefly why XMPP is ideal for these services, and also as a building block for situational awareness systems and in support of voice and video communication.
(7th Jan 2009)
by Email and over 'Air Gap'
Directory replication is an important feature of most directory services, commonly achieved by use of directory protocols. There are a number of situations where using directory protocols to perform replication does not work well, these include: HF Radio and other constrained links, system boundaries where only email traffic is allowed, directory gateways performing security checks and tactical directories with irregular network access. This paper looks at these scenarios, shows how directory replication over email and 'air gap' can address them and describes the architecture and key features of Isode's solution.
(3rd September 2008)
|Messaging Protocols for HF Radio
Messaging is important for military and other deployments of HF Radio. Formal Military Messaging (STANAG 4406) over HF Radio is described in a previous Isode White Paper. This paper looks at how to optimize STANAG 4406 messaging for point to point HF networks and how to provide Internet Messaging over multi-node and point to point HF networks.
(28th Aug 2008)
MMHS Performance over HF Radio and Satellite: STANAG 4406 Annex E Encoding
This white paper is the first of a set of papers reporting on measurements made of MMHS (Military Message Handling Systems) operating over HF Radio and Satellite. This paper looks at the encoding and compression of STANAG 4406 Annex E messages, which is common to both HF Radio and Satellite transmission.
(10th Jun 2008)
Performance over Satellite
This white paper is the second of a set of papers reporting on measurements made of MMHS (Military Message Handling Systems) operating over HF Radio and Satellite. This paper looks at operation over Satellite networks, and compares the performance of STANAG 4406 Annex E which is designed for constrained bandwidth networks with STANAG 4406 Annex A, which is intended for high speed networks.
(10th Jun 2008)
Radio & Network Centric Warfare
Modern military communications are a key component of Network Centric Warfare. HF Radios are used extensively for military communications, and, although very slow, provide effective long distance communication in a wide range of situations. This paper looks at how HF Radio fits with Network Centric Warfare, and looks at approaches for integrating HF Radios to maximize their effectiveness.
(9th Apr 2008)
|Military Messaging over HF Radio and Satellite using STANAG 4406 Annex E
Military Messages often need to be transferred over low bandwidth networks, in particular HF Radio and Satellite Networks. The two military specifications for this type of messaging environment are NATO's STANAG 4406 Annex E and ACP 142 developed by the CCEB (Combined Communications-Electronics Board – AU, CA, NZ, US, UK). This paper describes scenarios that require these special technologies, and then gives an overview of the technologies and how they address the technical problems.
(14th Feb 2008)
|Military Messaging over HF Radio: A comparison of ACP 127 and STANAG 4406 Annex E
ACP 127 is the older NATO standard for formal military messaging that is being replaced by STANAG 4406. Both standards are used over HF Radio, and for STANAG 4406, this is specified in Annex E. This paper looks at how both standards work, and shows the benefits of the newer technologies.
(14th Feb 2008)
|STANAG 5066: The Standard for Data Applications over HF Radio
STANAG 5066 is a NATO specification for running data applications over HF Radio. STANAG 5066 operates over an HF modem, and provides an interface for data applications to use and share an HF modem. STANAG 5066 provides core services to enable applications to operate efficiently over HF radio, and specifies a protocol that enables a clean separation between applications and modem/radio level. This paper describes STANAG 5066, and shows why it is key to deploying applications over HF Radio.
(14th Feb 2008)
|The Architecture of Isode's STANAG 4406 Annex E Solution
Military Messages often need to be transferred over low bandwidth networks, in particular HF Radio and Satellite Networks. Isode provides ACP 142 and STANAG 4406 Annex E as a part of its M-Switch X.400 product. This paper describes Isode's approach to implementing these protocols, and how this addresses basic and advanced operational problems, management approaches and integration with other components as part of a larger solution.
(14th Feb 2008)
|Why IP over HF Radio should be Avoided
HF Radios are important for military communications. IP is widely used and is the basis for most network communication. This paper looks at use of IP over HF Radio and the efficiency of different types of application over IP and concludes that applications intended for regular use over HF Radio should not use IP and should instead be directly integrated with STANAG 5066.
(14th Feb 2008)
Military Messaging for HF Radio and other Low Bandwidth Links
The general requirements and protocol architecture for military messaging over low bandwidth communications were described in the Isode White Paper Military Messaging Over Low Bandwidth Networks. This paper looks in more detail at how various server components are packaged together, looking at both software and hardware combinations, and showing how users and user agents fit into the system. The paper looks in detail at single user systems, from both hardware and software perspective.
(15th Feb 2007)
|Using Isode's Messaging and Directory Applications with a Data Diode
Data Diodes are low level hardware devices, with very high assurance, that allow data to flow in one direction while preventing data from flowing in the opposite direction. This white paper shows how Isode applications can be used in conjunction with a Data Diode to give high assurance one way flow of data.
(28th May 2009)
for Tactical Directory
Directory is an important component of Tactical Military operations. This paper looks at requirements for Tactical Directory, explains why there are special replication requirements, and that this is the only area where requirements differ significantly to other military directories.
(30th June 2005)