Approximately how many times can a DVD-RW or DVD+RW disc be rewritten?

Approximately how many times can a DVD-RW or DVD+RW disc be rewritten?

• 1000 times
• 10 times
• 100 times
• 1 time

EXPLANATION

As is the case with other optical storage media using phase-change technology there is a limit to the number of times the recording layer in a DVD-RW, DVD+RW and DVD-RAM disc can be reliably switched between its crystalline and amorphous states. It is estimated that a DVD-RW or DVD+RW disc can be rewritten approximately 1000 times and a DVD-RAM 100,000 times. In addition, these formats (under certain circumstances) employ defect management schemes to actively verify data and skip over or relocate problems to a spare area of the disc.

SOURCE

https://www.cnet.com/forums/discussions/how-many-times-can-you-rewrite-a-cd-rw-376723/

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Which Cmdlet is used to pair an SBC with for Microsoft Teams Direct Routing?

Which Cmdlet is used to pair an SBC with for Microsoft Teams Direct Routing?

• New-CsOnlinePSTNGateway
• New-CsTeamsPSTNGateway
• New-CsOnlineSBC
• New-CsDirectRoutingConfiguration

EXPLANATION

Pair the SBC to Direct Routing Service

The following are the three high-level steps to let you connect, or pair, the SBC to the Direct Routing interface:

• Connect to Skype for Business Online admin center using PowerShell
• Pair the SBC
• Validate the pairing

Connect to Skype for Business Online by using PowerShell

You can use a PowerShell session connected to the tenant to pair the SBC to the Direct Routing interface. To open a PowerShell session, please follow the steps outlined in Set up your computer for Windows PowerShell.

After you establish a remote PowerShell session, please validate that you can see the commands to manage the SBC. To validate the commands, type or copy/paste in the following in the PowerShell session and press Enter:

gcm *onlinePSTNGateway*

Your command will return the four functions shown here that will let you manage the SBCs.

CommandType    Name                       Version    Source

———–    —-                       ——-    ——

Function       Get-CsOnlinePSTNGateway    1.0        tmp_v5fiu1no.wxt

Function       New-CsOnlinePSTNGateway    1.0        tmp_v5fiu1no.wxt

Function       Remove-CsOnlinePSTNGateway 1.0        tmp_v5fiu1no.wxt

Function       Set-CsOnlinePSTNGateway    1.0        tmp_v5fiu1no.wxt

Pair the SBC to the tenant

To pair the SBC to the tenant, in the PowerShell session type the following and press Enter:

New-CsOnlinePSTNGateway -Fqdn <SBC FQDN> -SipSignallingPort <SBC SIP Port> -MaxConcurrentSessions <Max Concurrent Sessions the SBC can handle> -Enabled $true

SOURCE

http://teams-direct-routing.com/microsoft-teams-how-to/pair-teams-with-sbc/

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Which of the following are link state protocols?

Which of the following are link state protocols?

• RIP
• EIGRP
• OSPF
• BGP

EXPLANATION

Routing Information Protocol

The Routing Information Protocol is one of the oldest distance-vector routing protocols which employ the hop count as a routing metric. RIP prevents routing loops by implementing a limit on the number of hops allowed in a path from source to destination. The largest number of hops allowed for RIP is 15, which limits the size of networks that RIP can support.

Enhanced Interior Gateway Routing Protocol

Enhanced Interior Gateway Routing Protocol is an advanced distance-vector routing protocol that is used on a computer network for automating routing decisions and configuration. The protocol was designed by Cisco Systems as a proprietary protocol, available only on Cisco routers. Partial functionality of EIGRP was converted to an open standard in 2013 and was published with informational status as in 2016.

Open Shortest Path First

Open Shortest Path First is a routing protocol for Internet Protocol networks. It uses a link state routing algorithm and falls into the group of interior gateway protocols, operating within a single autonomous system. It is defined as OSPF Version 2 in RFC 2328 for IPv4. The updates for IPv6 are specified as OSPF Version 3 in RFC 5340. OSPF supports the Classless Inter-Domain Routing addressing model.

Border Gateway Protocol

Border Gateway Protocol is a standardized exterior gateway protocol designed to exchange routing and reachability information among autonomous systems on the Internet. The protocol is classified as a path vector protocol

SOURCE

https://learningnetwork.cisco.com/docs/DOC-17431

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How much native data you can store on a LTO-8 tape

How much native data you can store on a LTO-8 tape

• 24000 GB

• 12800 GB

• 12000 GB

• 25600 GB

EXPLANATION

LTO-8 offers a compressed storage capacity of 30TB (12TB native) using a 2.5:1 ratio, and a compressed transfer rate of 750 MB/sec. (360MB/sec. native). In addition, the new LTO-8 drives are backward compatible with LTO-7 tape media, allowing users to read/write any LTO-7 media. LTO-8 tape, like LTO-7, supports LTFS, WORM (Write Once Read Many) and AES 256-bit hardware encryption.

SOURCE

https://spectralogic.com/features/lto-8/

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What does SMTP stand for

What does SMTP stand for

• Simple Mail Transfer Protocol
• Smack Toilet Paper
• RAAAAAAAAAAAR!
• Small Mail Telemetry Pass

EXPLANATION

SMTP stands for Simple Mail Transfer Protocol. This is the generally accepted protocol. for outgoing e-mail. Use of SMTP. SMTP service is the side of e-mail that allows clients to send outgoing e-mail messages. to any valid e-mail address.

SMTP, is a protocol used to transmit email messages over the internet. The standard itself was first published in 1981, and it has been improved continuously to adapt to changes in technology and user needs

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All of these are general ports used for email except which one?

All of these are general ports used for email except which one?

• 25
• 22
• 587
• 110           

EXPLANATION

Common port numbers

Main article: List of TCP and UDP port numbers

The Internet Assigned Numbers Authority (IANA) is responsible for the global coordination of the DNS Root, IP addressing, and other Internet protocol resources. This includes the registration of commonly used port numbers for well-known Internet services.

The port numbers are divided into three ranges: the well-known ports, the registered ports, and the dynamic or private ports.

The well-known ports (also known as system ports) are those from 0 through 1023. The requirements for new assignments in this range are stricter than for other registrations, examples include:

• 20: File Transfer Protocol (FTP) Data Transfer
• 21: File Transfer Protocol (FTP) Command Control
• 22: Secure Shell (SSH) Secure Login
• 23: Telnet remote login service, unencrypted text messages
• 25: Simple Mail Transfer Protocol (SMTP) E-mail routing
• 53: Domain Name System (DNS) service
• 80: Hypertext Transfer Protocol (HTTP) used in the World Wide Web
• 110: Post Office Protocol (POP3)
• 119: Network News Transfer Protocol (NNTP)
• 123: Network Time Protocol (NTP)
• 143: Internet Message Access Protocol (IMAP) Management of digital mail
• 161: Simple Network Management Protocol (SNMP)
• 194: Internet Relay Chat (IRC)
• 443: HTTP Secure (HTTPS) HTTP over TLS/SSL

The registered ports are those from 1024 through 49151. IANA maintains the official list of well-known and registered ranges. The dynamic or private ports are those from 49152 through 65535. One common use for this range is for ephemeral ports. 

SOURCE

https://en.wikipedia.org/wiki/Port_(computer_networking)

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