Score Higher on Verified 500-710 | Video Infrastructure Implementation (VII) Exam Questions with Answers

The SIP message that is sent from the called endpoint after the call request is accepted is “200 OK”. This message indicates that the called endpoint has agreed to participate in the session and is ready to receive media. The “200 OK” message also contains the session description protocol (SDP) information that specifies the media capabilities and parameters of the called endpoint, such as the codec, the port number, and the encryption method. The “200 OK” message is sent as a response to the “INVITE” message that was sent by the caller to initiate the session. The caller then acknowledges the “200 OK” message by sending an “ACK” message, which completes the session establishment12

The other options are not valid SIP messages that are sent from the called endpoint after the call request is accepted. “Hello” is not a SIP message at all, but a common greeting. “404 OK” is a nonsensical combination of a SIP error code and a SIP status code. “404” means “Not Found”, which indicates that the requested user or service does not exist or is not available. “OK” means “Success”, which indicates that the request was fulfilled. These two codes are contradictory and cannot be used together. “Connect” is not a SIP message either, but a generic term for establishing a link or a communication34 References: SIP - Basic Call Flow - Online Tutorials Library, Understanding SIP INVITE method and messages - Wildix blog, Session Initiation Protocol - Wikipedia, Basic SIP Call Flows & Troubleshooting Commands - Cisco Community

 A SIP alias is an alternative address for a SIP URI, which is the standard format for identifying a user or a service in a SIP network. A SIP URI consists of a user part, an at sign (@), and a host part, such as user@host. The user part can be a username, a phone number, or any other identifier. The host part can be a domain name, an IP address, or any other network address. For example, alice@example.com, +1234567890@voip.com, and bob@192.168.1.1 are valid SIP URIs1.

A SIP alias is a way of creating multiple SIP URIs for the same user or service, using different user parts or host parts. For example, if a user has a SIP URI of john.doe@cisco.com, he can also have a SIP alias of jdoe@cisco.com, or john.doe@voip.cisco.com, or any other combination of user and host parts. A SIP alias can be useful for providing different contact options, simplifying dialing, or hiding the real SIP URI for privacy or security reasons2.

To configure a SIP alias, you need to have a SIP account with a SIP service provider that supports SIP alias, such as iptel.org. You also need to have a SIP device or application that can register and use the SIP alias, such as a VoIP phone, a softphone, or a router. You can create and manage your SIP alias using the web interface of your SIP service provider, or using the configuration settings of your SIP device or application2.

The correct format for a SIP alias is the same as the format for a SIP URI, which is user@host. Therefore, the option C. John.doe@cisco.com is the correct format for a SIPalias, as it has a user part (John.doe) and a host part (cisco.com) separated by an at sign (@). The other options are not correct formats for a SIP alias, because:

• A. 212-555-1212 : This is a phone number, not a SIP URI. It does not have a user part or a host part, and it does not have an at sign (@).
• B. +12125551212 : This is also a phone number, not a SIP URI. It does not have a user part or a host part, and it does not have an at sign (@).
• D. John.doe : This is only a user part, not a SIP URI. It does not have a host part, and it does not have an at sign (@).

References := Session Initiation Protocol (SIP) Parameters, How to configure SIP Alias | DrayTek

= Subzones are logical groupings of endpoints that are registered to an Expressway. Subzones are used for the following purposes1:

• Endpoints are assigned to a particular subzone by their alias or IP subnet: This is true, as the Expressway can use either the alias pattern or the IP subnet of the endpoint to determine which subzone it belongs to. The alias pattern is a regular expression that matches the endpoint’s SIP URI or H.323 ID. The IP subnet is a range of IP addresses that the endpoint falls into2.
• Subzones are used for bandwidth and authentication control of a logical grouping of endpoints within the registration list of the Expressway: This is true, as the Expressway can apply different bandwidth limits and authentication policies to different subzones. The bandwidth limits can be set for inbound and outbound calls, as well as for inter-subzone and intra-subzone calls. The authentication policies can be set to require or not require credentials from the endpoints in a subzone3.

The other options are not correct because:

• Subzones require the use of endpoint authentication: This is not true, as the Expressway can configure subzones to not require authentication from the endpoints. This can be useful for allowing guest or anonymous access to the video network3.
• Subzones are used for routing calls to peers in other parts of the network: This is not true, as the Expressway uses zones, not subzones, for routing calls to peers in other parts of the network. Zones are logical connections between Expressways or other SIP or H.323 entities, such as gateways, proxies, or servers. Zones can have different types, such as traversal, neighbor, or DNS4.
• Endpoints require the use of other endpoints for authentication: This is not true, as the Expressway does not use endpoints for authentication, but rather uses its own internal database or an external LDAP server. The Expressway can also use certificates or tokens for authentication, but these are not provided by other endpoints5.

References := 1: Cisco Expressway Basic Configuration Deployment Guide (X12.6) - Subzones [Cisco Expressway Series] - Cisco 2: Cisco Expressway Basic Configuration Deployment Guide (X12.6) - Assigning Endpoints to Subzones [Cisco Expressway Series] - Cisco 3: Cisco Expressway Basic Configuration Deployment Guide (X12.6) - Configuring Subzone Bandwidth and Authentication [Cisco Expressway Series] - Cisco 4: Cisco Expressway Basic Configuration Deployment Guide (X12.6) - Zones [Cisco Expressway Series] - Cisco 5: Cisco Expressway Basic Configuration Deployment Guide (X12.6) - Authentication [Cisco Expressway Series] - Cisco