biology

Z-Push

Z-Push is a biology topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Z-Push rather than just read about it. In short: Z-Push (presumably Z is for Zarafa) is a FOSS implementation of the Microsoft Exchange ActiveSync protocol which is used to synchronize email, personal contacts and other items between a central server and a mobile device. Z-Push enables any PHP and non-PHP based groupware package to become fully sync-able with any ActiveSync compliant device with an appropriate backend.

Key takeaways

Z-Push belongs to biology; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Z-Push to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Z-Push from memory before moving on to harder problems.

Reference excerpt

Z-Push (presumably Z is for Zarafa) is a FOSS implementation of the Microsoft Exchange ActiveSync protocol which is used to synchronize email, personal contacts and other items between a central server and a mobile device. Z-Push enables any PHP and non-PHP based groupware package to become fully sync-able with any ActiveSync compliant device with an appropriate backend. Currently, Z-Push includes four backends: the IMAP and the Maildir backends for e-mail synchronization, the vCard and the CardDAV backends for contact synchronization, CalDAV for calendar synchronization, stickynotes for Sticky Notes Synchronization and one for the Kopano and Zarafa package which is sold by allowing full synchronization of E-mail, Calendar, Contacts, and Tasks. There is also a 3rd party project that implements a Zimbra Backend, allowing Z-Push to be used with a ZCS server (Including opensource edition). Since version 2.3.0, released in July 2016, significant performance improvements have been achieved, as well as significantly lower memory usage. Connecting to Outlook 2013 and 2016 via EAS is also officially supported. With the optional Kopano Outlook Extension (available only for paid subscribers of Zarafa/Kopano), additional Outlook features are enabled such as Out of Office replies and opening of shared and public folders. The future sustainability of the Z-Push project was in question after Kopano (formerly Zarafa) announced that they would no longer be supporting the project. Z-Push now has a new maintainer from the community for future support of the project.

Technical background and architecture The ActiveSync protocol is a binary XML (WBXML) protocol across HTTP. The protocol is specifically designed with efficient use from mobile devices in mind. As such the protocol is optimized for low bandwidth, high latency connections. Also the protocol is designed for minimum number of whole request round trips. This means that the protocol can use many of the same techniques used to speed up access to websites. This is as opposed to IMAP or SMTP which is a two way handshaking TCP protocol which can be both quite slow and costly in terms of battery consumption across high latency connections. Getting ActiveSync instant push notification on mobile devices – particularly iOS devices – may well be the primary reason some people wish to use ActiveSync. However this will introduce significant additional server loading, so it should be carefully considered and monitored whether this is actually a desirable feature on the server. The client (i.e. phone) uses long polling HTTP with 30 minute timeouts on the HTTP requests. This means if no mail arrives there is no traffic on the TCP channel and the phone radios remain in low power receive only mode. However, server-side these HTTP requests are served as long polling web requests and processed in PHP. When the request comes in it consumes the resources of a web request - see further discussion below - and keeps this open for up to 30 minutes, or until a new message arrives, or the client device is switched off.

References

External links Z-Push project website Download Old Z-Push 2.2.x Install Z-Push from Repo Zimbra Backend for Z-Push

Worked examples

Example 1 — a first encounter with Z-Push

Start with the simplest possible case. Write down what Z-Push claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In biology, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Z-Push before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Z-Push ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Z-Push

In research: Z-Push appears in biology research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Z-Push in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Z-Push is common in secondary-school and first-year university syllabi. It links to neighbouring topics Data synchronization, Email, Groupware, so understanding it makes those chapters shorter.
In everyday life: Look for Z-Push outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

Ask Teacher Smith questions about this articleOpens your AI tutor with a question about “Z-Push” →

Affiliate

Preply — study more efficiently by working with a personal tutor. 50% off.

How to study Z-Push in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Z-Push means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Z-Push out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Z-Push in simple terms?

Why does Z-Push matter?

Because it connects several biology ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Z-Push?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Z-Push.