During the initial stages of information technologies, telecom carriers used leased lines to provide Layer 2 connections for enterprises. The disadvantages of leased lines are as follows: Constructing leased lines takes a long period. Leased lines require huge investments. Leased lines are difficult to manage. After the emergence of asynchronous transfer mode (ATM) and frame …
Continue reading What is the VPN connectionIntroduction Definition As an application of QoS in VPN services, MPLS HQoS includes hierarchical QoS (HQoS) at the public network side based on the peer PE/VPN instance, and interface-based QoS at the access side of users. MPLS HQoS offers practical QoS solutions to various services in the MPLS VPN. Purpose With the development of Virtual …
Continue reading MPLS HQoS ( Hierarchical QoS )Definition Hierarchical Quality of Service (HQoS) is a technology used to guarantee the bandwidth of multiple services of many users in the Differentiated Service (DiffServ) model through a queue scheduling mechanism. DiffServ is a type of the class-based QoS technology, and provides different services for different service flows. Therefore, in the DiffServ scheme, service …
Continue reading Hierarchical Quality of Service ( HQOS)Generally, an MPLS VPN architecture runs within an AS in which the VPN routing information is flooded on demand. The VPN routing information within the AS cannot be flooded to the AS of other SPs. To realize the exchange of VPN route information between different ASs, the inter-AS MPLS VPN model is introduced. The inter-AS …
Continue reading Inter-AS VPNThe public network tunnel of a Martini VLL can be an MPLS TE tunnel. Networking Requirements As shown in Figure 1, CE1 and CE2 belong to the same VPN. They access the MPLS backbone network through PE1 and PE2 respectively. OSPF is used as the IGP protocol on the MPLS backbone network. In this scenario, you …
Continue reading Configuring Martini VLL by Using MPLS TE TunnelsWhen BGP restarts, the peer relationship is re-established and the forwarding is interrupted. After Graceful Restart (GR) is enabled, traffic interruption can be avoided. The following roles are involved in the GR process: GR restarter: indicates a device that performs GR caused by a fault or triggered by the administrator. The GR restarter must be …
Continue reading BGP GR ( Graceful Restart )IS-IS Traffic Engineering (TE) is an extension of IS-IS to support MPLS TE. As specified in RFC 5305 and RFC 4205, IS-IS TE defines new TLVsand sub-TLVs in IS-IS LSPs to carry TE information, floods LSPs to implement the flooding and synchronization of TE information, and transmits TE information to the CSPF module. IS-IS TE supports MPLS …
Continue reading IS-IS TE