结算前48小时, the seller is required to inform the buyer of the specific pools related to a TBA position. EPN支持分配信息和交易细节, including trade terms and the securities intended for delivery on settlement date. 用于识别池中每个证券的代码(例如.g., MBS agency, product, coupon and maturity) are identical to those in the MBSD’s clearing system.
EPN users may exchange four different types of business messages to accomplish their notification needs. 其中三种信息类型是针对卖家的. 另一个是给买家的. Sellers use the ON (Original Notification) message type to notify the buyer of an outstanding TBA allocation. Sellers also use the CX (Cancel) message to notify a buyer to disregard the terms of a previously sent ON. 请注意，CX信息不能提交到FICC账户. 卖家也可以使用CC(取消和更正)消息, which allows the seller to notify a buyer to disregard the terms of a previously sent ON and to replace those pools with new pool details provided in the message. Buyers use the DK (Don’t Know) message type to notify a seller that they do not concur with the terms of a previously sent ON.
EPN消息的成功传递由EPN时间戳表示, and is independent of whether or not the recipient is logged on to the system. As a result, the number of failed trades and their associated costs has been dramatically reduced.
客户端s can use Messaging Queue (“MQ”) and RESTful Application Program Interface (“API”) to communicate with EPN. MBSD has also implemented EaSy Pool (ESP) as a communications front-end to the EPN system to provide a Web-based solution for the real-time exchange of pool information. Using a TCP/IP dial-up connection or a leased line through 存’s SMART communications network, ESP提供了“交钥匙”实现, 具有低启动成本和用户友好的消息“周转”功能. MQ Messaging and API are typically used by high-volume organizations willing to develop or purchase custom application interfaces between EPN and their internal allocation (optimization) systems.
EPN系统对所有消息进行实时处理. 当用户向EPN提交消息时, EPN performs basic edits and validation checks to ensure essential data integrity. 随后, EPN timestamps each message and forwards the message to the outbound queue of the recipient so that it can be returned to the sender. The time stamp placed by EPN on the message is the sender’s evidence of “good delivery,也就是说, 通知是在48小时内发出的(美国东部时间15:00:00之前), 在东部时间12:15:00之前发送抄送消息).
由于EPN是基于队列的系统，因此发送方无法接收到忙音信号. Message recipients may connect to EPN at any time throughout the day to retrieve messages from their queues or submit messages to EPN. Volume and/or turn-around objectives determine how much connect time is necessary.