500-444 Exam Dumps : Cisco Contact Center Enterprise Implementation and Troubleshooting

A certificate authority (CA) is a trusted entity that issues digital certificates for websites and other entities. CAs validate a website domain and, depending on the type of certificate, the ownership of the website, and then issue TLS/SSL certificates that are trusted by web browsers like Chrome, Safari and Firefox. Thus, CAs help keep the internet a safer place by verifying websites and other entities to enable more trust in online communications and transactions. Some of the roles of a CA in a trusted third-party CA certificate are:

• To provide validation of certificate requests: A CA verifies the identity and authenticity of the certificate requester before issuing a certificate. The CA may use different methods of validation, such as domain validation, organization validation, or extended validation, depending on the type and level of assurance of the certificate. The CA may also check the revocation status of the certificate or the certificate chain to ensure that the certificate is not expired or revoked.
• To issue a CA signed Identity certificates: A CA signs the certificate with its own private key, which attests to the validity and integrity of the certificate. The CA also provides the certificate with a serial number, a validity period, and other attributes. The CA signed certificate can be used by the certificate holder to prove its identity and establish secure connections with other parties.

References:

• What is a CA? Certificate Authorities Explained
• The Role of Certificate Authorities
• The 5 most frequently Asked Questions about Certificate Authority (CA)

 The keytool command that lists certificates in the cacerts file is B: keytool -list -keystore cacerts. This command will display the aliases and fingerprints of all the certificates in the cacerts file, which is the default truststore for Java applications1. The cacerts file contains the root and intermediate certificates of various certificate authorities (CAs) that are trusted by Java2.

The other options are incorrect because:

• A: keytool -list -showinfo is not a valid keytool command, as the -showinfo option does not exist. The closest option is -v or -verbose, which will display more details about each certificate, such as the owner, issuer, serial number, validity period, signature algorithm, and extensions1.
• C: keytool -list cacerts is not a complete keytool command, as it is missing the -keystore option, which is required to specify the name or path of the keystore file to be listed. Without the -keystore option, the keytool command will assume the default keystore file, which is usually named .keystore in the user’s home directory1.
• D: keytool -list -alias is also not a complete keytool command, as it is missing the value of the -alias option, which is used to specify the alias of a particular entry in the keystore file to be listed. Without the value of the -alias option, the keytool command will display an error message, such as "keytool error: java.lang.Exception: Alias does not exist"1.

References:

1: keytool - Key and Certificate Management Tool 2: How to check a Certificate is in default cacerts 3: java - How to view and edit cacerts file? - Stack Overflow 4: HOW TO: Import or list certificates from Java cacerts file using … 5: Keytool: List Certificate - Java Certs - ShellHacks

A voice gateway (VGW) is a device that connects a traditional telephony network, such as a TDM trunk, to a voice over IP (VoIP) network, such as a Cisco Unified Communications Manager (CUCM) cluster. A VGW performs signaling and media conversion between the two networks, and can also provide supplementary services, such as call routing, digit manipulation, transcoding, conferencing, and fax relay. A VGW can be a standalone device, such as a Cisco Integrated Services Router (ISR), or a software module, such as a Cisco Unified Border Element (CUBE). A CUBE is a special type of VGW that can also provide security, demarcation, and interworking functions for VoIP calls. A CUBE can be deployed between two VoIP networks, such as CUCM and a service provider SIP trunk, or between a TDM trunk and a VoIP network, in which case it acts as both a CUBE and a VGW. A CUCM is not a VGW, but a call control platform that manages VoIP endpoints, such as IP phones, and interacts with VGWs for call routing and signaling. A CUSP is a Cisco Unified SIP Proxy, which is a device that provides SIP routing and load balancing for VoIP networks. A CUSP is not a VGW, but a SIP proxy server that can work with CUCM and CUBE to optimize SIP call flows. References:

• Troubleshooting Cisco Contact Center Enterprise (CCET), Module 1: Voice Gateway Overview1
• Cisco Contact Center Enterprise Implementation and Troubleshooting (CCEIT), Module 2: Voice Gateway Configuration2
• Cisco Unified Border Element Configuration Guide3
• Cisco Unified SIP Proxy Configuration Guide4