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Advantages of Fast Web Services

ASN.1 tools

​ASN.1 tools may be used to aid in the development of SOAP processors. XML-based SOAP processors are, for the most part, written by hand, and the W3C XML Schema for SOAP may be used as a guide, since XML-based binding tools are unlikely to aid in the development of optimal XML-based SOAP processors. The ASN.1 approach allows for choice of either tools or hand crafting to develop SOAP processors.

Optimized features

​The ASN.1 Schema for SOAP provides a number of optimized features (beyond compaction and efficient processing offered by the use of ASN.1 and the Packed Encoding Rules) for SOAP nodes:

  1. The ASN.1 SOAP body is explicitly separated from the ASN.1 SOAP fault. This makes faults easier to identify and manage.
  2. Recursive fault sub-code values for XML SOAP messages are flattened to a sequence of fault sub-code values for ASN.1 SOAP messages. This enables a decoder to know how many fault sub-codes there are before decoding.
  3. Relative object identifiers may be used instead of qualified names. Messages for service descriptions can be annotated with relative object identifiers and such identifiers, when encoded, can be more compact that qualified names, resulting in smaller message sizes.
  4. Default values for all attribute related ASN.1 SOAP header block components are specified.
  5. Enumerated values for SOAP specified fault codes instead of qualified names

Compact messages and efficient processing



ASN.1 SOAP messages encoded using the ASN.1 Packed Encoding Rules generally provides for the operation of Web services that require less processing power (and hence provide a higher transaction processing rate) and that require less network bandwidth than use of the character encoding of XML data in conventional Web services. This can be advantageous in a number of domains:


1. Constrained devices, such as mobile phones, smart cards or even RFIDs (Radio-Frequency IDentification), that have limited processing power, memory and battery life.

There is no equivalent Moore's law for battery technology (battery life is not doubling every 18 months).

2. Bandwidth restricted systems, such as wireless networks.

 

Radio frequencies for wireless networks, such as the mobile phone GSM network (Global System for Mobile Communications), can be fixed for 10 years. There is no equivalent Moore's law for radio frequencies (bandwidth is not doubling every 18 months).


3. High throughput transaction systems, such as systems required to process a required number SOAP messages per second from many clients.

 

Research has shown that doubling the number of network nodes can result in an increase in the interconnections between nodes to a power of 7 or 8, which is much larger than an increase in processing power obtained from a doubling of transistor density. This implies many more messages that need to be processed by systems that are increasingly being outpaced by the network.

Efficient processing for SOAP intermediaries

​SOAP intermediaries by their definition have the potential to process many more SOAP messages than initial SOAP senders and ultimate SOAP receivers. SOAP intermediaries processing ASN.1 SOAP messages may easily identify ASN.1 SOAP header blocks for processing (including decoding) while skipping (and copying) other SOAP header blocks (destined for other SOAP intermediaries or the SOAP ultimate receiver) and the SOAP body since they will managed as a (length prefixed) sequence of octets.

ASN.1 SOAP intermediaries may also manage ASN.1 SOAP faults efficiently since a fault will always occur at the end of a message (before the SOAP header blocks) and will be guaranteed to start at a byte boundary if header blocks are present. Therefore it is not necessary to decode the fault unless the intermediary performs processes not specified by the SOAP processing model.