What internet protocol is used to stream videos and audio on the internet?

What internet protocol is used to stream videos and audio on the internet?

• UDP
• IPX
• IP
• TCP

EXPLANATION

Drawbacks of using TCP for live video:

1. Typically live video-streaming appliances are not designed with TCP streaming in mind. If you use TCP, the OS must buffer the unacknowledged segments for every client. This is undesirable, particularly in the case of live events; presumably your list of simultaneous clients is long due to the singularity of the event. Pre-recorded video-casts typically don't have as much of a problem with this because viewers stagger their replay activity; therefore TCP is more appropriate for replaying a video-on-demand.
2. IP multicast significantly reduces video bandwidth requirements for large audiences; TCP prevents the use of IP multicast, but UDP is well-suited for IP multicast.
3. Live video is normally a constant-bandwidth stream recorded off a camera; pre-recorded video streams come off a disk. The loss-backoff dynamics of TCP make it harder to serve live video when the source streams are at a constant bandwidth (as would happen for a live-event). If you buffer to disk off a camera, be sure you have enough buffer for unpredictable network events and variable TCP send/backoff rates. UDP gives you much more control for this application since UDP doesn't care about network transport layer drops.

FYI, please don't use the word "packages" when describing networks. Networks send "packets". 

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Simple mail transfer protocol (SMTP) commonly uses __________ as the transport layer protocol for electronic mail transfer.

Simple mail transfer protocol (SMTP) commonly uses __________ as the transport layer protocol for electronic mail transfer.

• DCCP
• TCP
• UDP
• SCTP 

EXPLANATION

The Simple Mail Transfer Protocol (SMTP) is a communication protocol for electronic mail transmission. As an Internet standard, SMTP was first defined in 1982 by RFC 821, and updated in 2008 by RFC 5321 to Extended SMTP additions, which is the protocol variety in widespread use today. Mail servers and other message transfer agents use SMTP to send and receive mail messages. Proprietary systems such as Microsoft Exchange and IBM Notes and webmail systems such as Outlook.com, Gmail and Yahoo! Mail may use non-standard protocols internally, but all use SMTP when sending to or receiving email from outside their own systems.
SMTP servers commonly use the Transmission Control Protocol on port number 25.
User-level email clients typically use SMTP only for sending messages to a mail server for relaying, typically submit outgoing email to the mail server on port 587 or 465 as per RFC 8314. For retrieving messages, IMAP and POP3 are standard, but proprietary servers also often implement proprietary protocols, e.g., Exchange ActiveSync.

 

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If you're going to secure your Exchange server, the best place for the front-end server is...

If you're going to secure your Exchange server, the best place for the front-end server is...

• At a hosted location
• Outside the firewall
• The internal network
• The internal network with ISA in the perimeter 

EXPLANATION

The generally accepted way of implementing a front end / backend configuration involves placing an ISA Server in front of the front end server.
The idea behind this configuration is that remote clients never interact directly with the front end server. Instead, the ISA Server is provided with a copy of the front end server's certificate, which allows it to impersonate the front end Exchange Server. Remote clients never actually communicate with the front end Exchange Server. Instead, remote clients communicate with the ISA server. The ISA server acts as a proxy server and forwards HTTP requests to the front end Exchange Server.
Part of the ISA server's job is to act as an application firewall for Exchange Server. What this means is that ISA server knows what types of communications are considered normal for an Exchange Server environment. It is therefore able to filter out abnormal and potentially malicious packets.
The merits of using an ISA server are sometimes debated though. The reason why this is a debated topic is that ISA Server is a software based firewall sitting on top of a Windows operating system. Some people feel that it is therefore vulnerable to the same types of attacks that any other Windows server would be.
My take on this issue is that ISA Server should be considered an essential part of a front end / back end configuration. ISA Server is not a generic firewall. It was developed by Microsoft with Exchange in mind. It contains lots of Exchange specific filtering rules that will help to keep your Exchange Server secure. At the same time though, I believe that the fact that ISA Server rides on top of a Windows operating system does pose a security threat. In my opinion, the best way to counter this threat is to place a hardware-based firewall at your network's perimeter and then have your hardware firewall forward the inbound HTTP requests to an ISA Server located behind it.

 

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Which of the following methods is not a secure way to connect clients to Exchange?

Which of the following methods is not a secure way to connect clients to Exchange?

• Outlook using MAPI/RPC
• Outlook Web Access over HTTPS
• Outlook using RPC over HTTPS
• Outlook using IMAP4 with SSL 

EXPLANATION

The point they're making is that "traditional RPC" sometimes uses unusual low-level network protocols that often get blocked by corporate firewalls. Because SOAP uses HTTP, it's traffic is "indistinguishable" from normal web page views, and so is not caught out by these firewalls. Not too sure about the security point, I think they're probably implying that HTTP can easily be secured over HTTPS and that proprietary RPC protocols often don't. Of course, this is protocol dependant, not all RPC protocols will be insecure, and many of them can be tunnelled over HTTPS.

RPC over HTTP, also known as Outlook Anywhere, is a legacy method of connectivity and transport between Outlook for Windows and Exchange. In May 2014, Microsoft introduced MAPI over HTTP as a replacement for RPC over HTTP.
Starting on October 31, 2017, RPC over HTTP will no longer be a supported protocol for accessing mail data from Exchange Online. Starting on this date, the following conditions will apply:

1. Microsoft will not provide support for RPC over HTTP issues (regular or custom).
2. No code fixes or updates to resolve problems that are unrelated to security will be released.

Additionally, for Office versions that support MAPI over HTTP, Microsoft may elect to ignore existing registry keys that customer are using in order to force RPC over HTTP use.

 

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1024 bits are equal to how many bytes?

1024 bits are equal to how many bytes?

• 128 bytes
• 1 byte
• 64 bytes
• 32 bytes 

EXPLANATION

How to convert bits to Bytes: Enter a value in the bits field and click on the "Calculate Bytes" button. Your answer will appear in the Bytes field.

Conversion Definitions

The following is a list of definitions relating to conversions between bits and Bytes.

What is a bit (b)?

A bit is a unit used to measure digital storage and is based on "Binary multiples of bits". The symbol for bit is b. There are 8 bits in a Byte.

What is a Byte (B)?

A Byte is a unit used to measure digital storage and is based on "Binary multiples of Bytes". The symbol for Byte is B. There are 0.125 Bytes in a bit.

Conversion Formula

Let's take a closer look at the conversion formula so that you can do these conversions yourself with a calculator or with an old-fashioned pencil and paper.

The formula to convert from bits to Bytes is:

Bytes = bits ÷ 8

Conversion Example

Next, let's look at an example showing the work and calculations that are involved in converting from bits to Bytes (b to B).

bit to Byte Conversion Example

Task: Convert 3,000 bits to Bytes (show work)

Formula:
bits ÷ 8 = Bytes

Calculations:
3,000 bits ÷ 8 = 375 Bytes

Result:
3,000 bits is equal to 375 Bytes

SOURCE

https://duckduckgo.com/?q=bit+to+bytes+conversion&t=ffcm&atb=v1-1&ia=answer

 

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In PowerShell, what is "splatting"?

In PowerShell, what is "splatting"?

• A way to pass multiple parameters to a cmdlet
• A way to define many variables at once
• An error state where many things failed at once
• A way to dump the full contents of the pipeline 

EXPLANATION

Splatting to pass parameters to commands in PowerShell

Splatting is a method of passing a collection of parameter values to a command as unit. PowerShell associates each value in the collection with a command parameter. Splatted parameter values are stored in named splatting variables, which look like standard variables, but begin with an At symbol (@) instead of a dollar sign ($). The At symbol tells PowerShell that you are passing a collection of values, instead of a single value.
Splatting makes your commands shorter and easier to read. You can re-use the splatting values in different command calls and use splatting to pass parameter values from the $PSBoundParameters automatic variable to other scripts and functions.
Beginning in Windows PowerShell 3.0, you can also use splatting to represent all parameters of a command.

SYNTAX

<CommandName> <optional parameters> @<HashTable> <optional parameters>
<CommandName> <optional parameters> @<Array> <optional parameters>

To provide parameter values for positional parameters, in which parameter names are not required, use the array syntax. To provide parameter name and value pairs, use the hash table syntax. The splatted value can appear anywhere in the parameter list.
When splatting, you do not need to use a hash table or an array to pass all parameters. You may pass some parameters by using splatting and pass others by position or by parameter name. Also, you can splat multiple objects in a single command just so you pass no more than one value for each parameter.

 

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Twitter is an example of what type of cloud service?

Twitter is an example of what type of cloud service?

• SaaS
• IaaS
• PaaS
• DBaaS 

EXPLANATION

SaaS is also known as “on-demand software”. Users of SaaS rather than fully buy the license of various software hire the software at regular intervals and use it through an Internet browser. The variety of software provided by SaaS is very broad. There are a number of software used by SaaS from companies such as end users that employs in content management, human resources management, accounting, ERP, customer relationship management and other relevant areas.

The software-as-a-service type of cloud computing grows very quickly, while the largest market for software-as-a-service electricity is customer relationship management.
In this service model, the cloud-based applications are offered to the customer as a service on request. It is a single instance of the service running on remote computers “in the cloud”, owned and operated by others, and connected to the users' computers over the Internet and typically a web browser. Social networking sites like Facebook, Twitter, Flickr and Google are all examples of SaaS, although users are able to access the services through any Internet-enabled device.

 

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