polishing

[skm-ma-ws1314.git] / sec-discussion.tex

diff --git a/sec-discussion.tex b/sec-discussion.tex
index 6305ab4..0e4fe59 100644 (file)
--- a/sec-discussion.tex
+++ b/sec-discussion.tex
@@ -59,7 +59,7 @@ be used in existing infrastructures, and is also focused on multiple platforms
 like embedded systems and servers. Web Services can be very flexible and
 composable, and discovery is already specified, however, this also comes at a
 cost: web services are enclosed in SOAP, which is enclosed in HTTP, which is
-transported over TCP, which introduces very much overhead, except with SOAP
+transported over TCP, which introduces very much overhead, especially with SOAP
 being based on verbose XML. IPv6 support is only partially implemented.
 For communication, standard APIs can be used.
 
@@ -70,10 +70,10 @@ protocol, there is the need to implement at least an XML parser on each node,
 which comes with protocol overhead and increased code size. However Klauck and
 Kirsche show that with good optimization (in the code as well as in the
 procotol), a complete stack can be implemented in 12 kByte of ROM, which leaves
-enough space for other applications to build onto it. As compared to Web
+enough space for other applications to be built onto it. As compared to Web
 Services, Chatty Things are probably not as flexible, but they have less
 overhead, even when using XML, while MQTT and CoAP provide less flexibility for
-future enhancement, therefore less protocol overhead and easier parsing.
+future enhancement, but less protocol overhead and easier parsing.
 
 With TCP, mDNS, DNS-SD and XMPP as foundation, the proposed architecture builds
 on reliable and established standards, which allows it to reuse Chatty Things in
@@ -85,7 +85,7 @@ which is caused by the lack of support for Multi-User Chats in XEP-0174
 (Serverless Messaging). If this gap can be closed, or a different way for topic
 filtering in distributed networks is found, the server can be
 eliminated and what remains is truly distributed network without the need for
-any central infrastructure, therefore eliminating every single point of failure
+any central infrastructure, therefore eliminating most single points of failure
 in the system.
 
 It is always hard to trade flexibility and accessibility for efficiency. The
@@ -96,6 +96,23 @@ specialized software. In terms of efficiency, it chooses a common ground between
 binary protocols and Web Services, which were originally developed for servers
 with much less resource constraints as embedded systems.
 
+Nonetheless, there are a few additional XEPs which can be implemented to further
+increase the effictivity of Chatty Things. XEP-0322 (Efficient XML Interchange
+Format)~\cite{xep0322} describes how XMPP stanzas sent between a server and a
+client can be compressed, therefore effectively reducing the overhead introduced
+by XML. A client and a server can then negotiate a compressed stream inside
+their existing XMPP stream and exchange \code{<compress>} stanzas which contain
+the payload.
+
+The documents XEP-0324 through XEP-0326 contain specifications targeted
+especially to the Internet of Things:
+
 \todo{additional XEPs, example XML stream with sensor data}
 
+\begin{itemize}
+ \item asdf
+ \item asdfasdf
+ \item lkjlkj
+\end{itemize}
+
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